![Brass lectern in the form of an eagle attributed to Aert van Tricht the Elder, Limburg (Netherlands), c](https://upload.wikimedia.org/wikipedia/commons/f/fe/Brass_lectern_in_the_form_of_an_eagle_attributed_to_Aert_van_Tricht_the_Elder%2C_Limburg_%28Netherlands%29%2C_c._1500%2C_The_Cloisters.jpg)
Brass is an
alloy
An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductilit ...
of
copper (Cu) and
zinc (Zn), in proportions which can be varied to achieve different mechanical, electrical, and chemical properties. It is a
substitutional alloy
An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductility, ...
: atoms of the two constituents may replace each other within the same crystal structure.
Brass is similar to
bronze, another copper alloy, that uses
tin
Tin is a chemical element with the symbol Sn (from la, stannum) and atomic number 50. Tin is a silvery-coloured metal.
Tin is soft enough to be cut with little force and a bar of tin can be bent by hand with little effort. When bent, t ...
instead of zinc. Both bronze and brass may include small proportions of a range of other
elements including
arsenic (As),
lead (Pb),
phosphorus (P),
aluminium (Al),
manganese (Mn), and
silicon (Si). Historically, the distinction between the two alloys has been less consistent and clear, and modern practice in museums and
archaeology
Archaeology or archeology is the scientific study of human activity through the recovery and analysis of material culture. The archaeological record consists of artifacts, architecture, biofacts or ecofacts, sites, and cultural landsca ...
increasingly avoids both terms for historical objects in favor of the more general "
copper alloy
Copper alloys are metal alloys that have copper as their principal component. They have high resistance against corrosion. The best known traditional types are bronze, where tin is a significant addition, and brass, using zinc instead. Both of t ...
".
Brass has long been a popular material for decoration due to its bright, gold-like appearance; being used for
drawer pull
A drawer pull (wire pull or simply pull) is a handle to pull a drawer out of a chest of drawers, cabinet or other furniture piece.
A drawer pull often includes a plate to which the handle is fastened. The handle may swing from one or two mou ...
s and
doorknobs. It has also been widely used to make utensils because of its low melting point, high workability (both with hand tools and with modern
turning
Turning is a machining process in which a cutting tool, typically a non-rotary tool bit, describes a helix toolpath by moving more or less linearly while the workpiece rotates.
Usually the term "turning" is reserved for the generation ...
and
milling machines), durability, and
electrical
Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described ...
and
thermal conductivity
The thermal conductivity of a material is a measure of its ability to conduct heat. It is commonly denoted by k, \lambda, or \kappa.
Heat transfer occurs at a lower rate in materials of low thermal conductivity than in materials of high thermal ...
.
Brass is still commonly used in applications where corrosion resistance and low
friction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction:
*Dry friction is a force that opposes the relative lateral motion of ...
are required, such as
lock
Lock(s) may refer to:
Common meanings
*Lock and key, a mechanical device used to secure items of importance
*Lock (water navigation), a device for boats to transit between different levels of water, as in a canal
Arts and entertainment
* ''Lock ...
s,
hinges,
gear
A gear is a rotating circular machine part having cut teeth or, in the case of a cogwheel or gearwheel, inserted teeth (called ''cogs''), which mesh with another (compatible) toothed part to transmit (convert) torque and speed. The basic ...
s,
bearings,
ammunition casings,
zipper
A zipper, zip, fly, or zip fastener, formerly known as a clasp locker, is a commonly used device for binding together two edges of fabric or other flexible material. Used in clothing (e.g. jackets and jeans), luggage and other bags, camping ...
s,
plumbing
Plumbing is any system that conveys fluids for a wide range of applications. Plumbing uses pipes, valves, plumbing fixtures, tanks, and other apparatuses to convey fluids. Heating and cooling (HVAC), waste removal, and potable water deliv ...
,
hose coupling
A hose coupling is a connector on the end of a hose to connect (or ''couple'') it with another hose or with a tap or a hose appliance, such as an irrigation sprinkler. It is usually made of steel, brass, stainless steel, aluminium or plastic ...
s,
valve
A valve is a device or natural object that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways. Valves are technically fitting ...
s, and
electrical plugs and sockets. It is used extensively for
musical instruments
A musical instrument is a device created or adapted to make musical sounds. In principle, any object that produces sound can be considered a musical instrument—it is through purpose that the object becomes a musical instrument. A person who pl ...
such as
horn
Horn most often refers to:
*Horn (acoustic), a conical or bell shaped aperture used to guide sound
** Horn (instrument), collective name for tube-shaped wind musical instruments
*Horn (anatomy), a pointed, bony projection on the head of various ...
s and
bell
A bell is a directly struck idiophone percussion instrument. Most bells have the shape of a hollow cup that when struck vibrates in a single strong strike tone, with its sides forming an efficient resonator. The strike may be made by an inte ...
s. The composition of brass, generally 66% copper and 34% zinc, makes it a favorable substitute for copper in
costume jewelry
Costume or fashion jewelry includes a range of decorative items worn for personal adornment that are manufactured as less expensive ornamentation to complement a particular fashionable outfit or garmentBaker, Lillian. Fifty Years of Collectabl ...
and
fashion jewelry, as it exhibits greater resistance to corrosion. Brass is not suitable for such items as boat propellers because the zinc reacts with minerals in salt water, leaving porous copper behind. The tin in bronze will not react with these minerals.
Brass is often used in situations in which it is important that
spark
Spark commonly refers to:
* Spark (fire), a small glowing particle or ember
* Electric spark, a form of electrical discharge
Spark may also refer to:
Places
* Spark Point, a rocky point in the South Shetland Islands
People
* Spark (surname)
* ...
s not be struck, such as in fittings and tools used near flammable or explosive materials.
Properties
![Microstructure of rolled and annealed brass; magnification 400X](https://upload.wikimedia.org/wikipedia/commons/6/69/Microstructure_of_rolled_and_annealed_brass%3B_magnification_400X.jpg)
Brass is more malleable than bronze or zinc. The relatively low
melting point
The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depen ...
of brass (, depending on composition) and its flow characteristics make it a relatively easy material to cast. By varying the proportions of copper and zinc, the properties of the brass can be changed, allowing hard and soft brasses. The
density
Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematical ...
of brass is .
Today, almost 90% of all brass alloys are recycled. Because brass is not
ferromagnetic, ferrous scrap can be separated from it by passing the scrap near a powerful magnet. Brass scrap is melted and recast into
billets
A billet is a living-quarters to which a soldier is assigned to sleep. Historically, a billet was a private dwelling that was required to accept the soldier.
Soldiers are generally billeted in barracks or garrisons when not on combat duty, al ...
that are extruded into the desired form and size. The general softness of brass means that it can often be machined without the use of
cutting fluid
Cutting fluid is a type of coolant and lubricant designed specifically for metalworking processes, such as machining and stamping. There are various kinds of cutting fluids, which include oils, oil-water emulsions, pastes, gels, aerosols (mists) ...
, though there are exceptions to this.
Aluminium makes brass stronger and more corrosion-resistant. Aluminium also causes a highly beneficial hard layer of
aluminium oxide (Al
2O
3) to be formed on the surface that is thin, transparent, and self-healing. Tin has a similar effect and finds its use especially in
seawater
Seawater, or salt water, is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% (35 g/L, 35 ppt, 600 mM). This means that every kilogram (roughly one liter by volume) of seawater has appr ...
applications (naval brasses). Combinations of iron, aluminium, silicon, and manganese make brass
wear
Wear is the damaging, gradual removal or deformation of material at solid surfaces. Causes of wear can be mechanical (e.g., erosion) or chemical (e.g., corrosion). The study of wear and related processes is referred to as tribology.
Wear in ...
- and
tear-resistant. The addition of as little as 1% iron to a brass alloy will result in an alloy with a noticeable magnetic attraction.
![Diagramme binaire Cu Zn](https://upload.wikimedia.org/wikipedia/commons/9/9c/Diagramme_binaire_Cu_Zn.svg)
Brass will
corrode
Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engin ...
in the presence of moisture,
chloride
The chloride ion is the anion (negatively charged ion) Cl−. It is formed when the element chlorine (a halogen) gains an electron or when a compound such as hydrogen chloride is dissolved in water or other polar solvents. Chloride sa ...
s,
acetates,
ammonia
Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous wa ...
, and certain acids. This often happens when the copper reacts with sulfur to form a brown and eventually black surface layer of
copper sulfide
Copper sulfides describe a family of chemical compounds and minerals with the formula CuxSy. Both minerals and synthetic materials comprise these compounds. Some copper sulfides are economically important ores.
Prominent copper sulfide mineral ...
which, if regularly exposed to slightly acidic water such as urban rainwater, can then oxidize in air to form a
patina of green-blue
copper carbonate Copper carbonate may refer to :
;Copper (II) compounds and minerals
* Copper(II) carbonate proper, (neutral copper carbonate): a rarely seen moisture-sensitive compound.
* Basic copper carbonate (the "copper carbonate" of commerce), actually a cop ...
. Depending on how the patina layer was formed, it may protect the underlying brass from further damage.
Although copper and zinc have a large difference in
electrical potential
The electric potential (also called the ''electric field potential'', potential drop, the electrostatic potential) is defined as the amount of work energy needed to move a unit of electric charge from a reference point to the specific point in ...
, the resulting brass alloy does not experience internalized
galvanic corrosion because of the absence of a corrosive environment within the mixture. However, if brass is placed in contact with a more noble metal such as silver or gold in such an environment, the brass will corrode galvanically; conversely, if brass is in contact with a less-noble metal such as zinc or iron, the less noble metal will corrode and the brass will be protected.
Lead content
To enhance the machinability of brass,
lead
Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cu ...
is often added in concentrations of about 2%. Since lead has a lower
melting point
The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depen ...
than the other constituents of the brass, it tends to migrate towards the
grain boundaries
In materials science, a grain boundary is the interface between two grains, or crystallites, in a polycrystalline material. Grain boundaries are two-dimensional defects in the crystal structure, and tend to decrease the electrical and thermal ...
in the form of globules as it cools from casting. The pattern the globules form on the surface of the brass increases the available lead surface area which, in turn, affects the degree of leaching. In addition, cutting operations can smear the lead globules over the surface. These effects can lead to significant lead leaching from brasses of comparatively low lead content.
In October 1999, the California State Attorney General sued 13 key manufacturers and distributors over lead content. In laboratory tests, state researchers found the average brass key, new or old, exceeded the
California Proposition 65 limits by an average factor of 19, assuming handling twice a day.
[News & Alerts – California Dept. of Justice – Office of the Attorney General](_blank)
12 October 1999. , In April 2001 manufacturers agreed to reduce lead content to 1.5%, or face a requirement to warn consumers about lead content. Keys plated with other metals are not affected by the settlement, and may continue to use brass alloys with a higher percentage of lead content.
Also in California, lead-free materials must be used for "each component that comes into contact with the wetted surface of pipes and
pipe fittings, plumbing fittings and fixtures". On 1 January 2010, the maximum amount of lead in "lead-free brass" in California was reduced from 4% to 0.25% lead.
[AB 1953 Assembly Bill – Bill Analysis](_blank)
. Info.sen.ca.gov. Retrieved on 9 December 2011.
Corrosion-resistant brass for harsh environments
![00 BMA Automation Sampling cock](https://upload.wikimedia.org/wikipedia/commons/6/62/00_BMA_Automation_Sampling_cock.JPG)
Dezincification-resistant (
DZR or DR) brasses, sometimes referred to as CR (
corrosion
Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engi ...
resistant) brasses, are used where there is a large corrosion risk and where normal brasses do not meet the requirements. Applications with high water temperatures,
chloride
The chloride ion is the anion (negatively charged ion) Cl−. It is formed when the element chlorine (a halogen) gains an electron or when a compound such as hydrogen chloride is dissolved in water or other polar solvents. Chloride sa ...
s present or deviating water qualities (
soft water) play a role. DZR-brass is excellent in water
boiler
A boiler is a closed vessel in which fluid (generally water) is heated. The fluid does not necessarily boil. The heated or vaporized fluid exits the boiler for use in various processes or heating applications, including water heating, centr ...
systems. This brass alloy must be produced with great care, with special attention placed on a balanced composition and proper production temperatures and parameters to avoid long-term failures.
An example of DZR brass is the C352 brass, with about 30% zinc, 61–63% copper, 1.7–2.8% lead, and 0.02–0.15% arsenic. The lead and arsenic significantly suppress the zinc loss.
"Red brasses", a family of alloys with high copper proportion and generally less than 15% zinc, are more resistant to zinc loss. One of the metals called "red brass" is 85% copper, 5% tin, 5% lead, and 5% zinc. Copper alloy C23000, which is also known as "red brass", contains 84–86% copper, 0.05% each iron and lead, with the balance being zinc.
Another such material is
gunmetal
Gun metal, also known as red brass in the United States, is a type of bronze; an alloy of copper, tin and zinc. Proportions vary but 88% copper, 8–10% tin, and 2–4% zinc is an approximation. Originally used chiefly for making guns, it has ...
, from the family of red brasses. Gunmetal alloys contain roughly 88% copper, 8-10% tin, and 2-4% zinc. Lead can be added for ease of machining or for bearing alloys.
"Naval brass", for use in seawater, contains 40% zinc but also 1% tin. The tin addition suppresses zinc leaching.
The
NSF International requires brasses with more than 15% zinc, used in
piping and plumbing fitting
A fitting or adapter is used in pipe systems to connect straight sections of pipe or tube, adapt to different sizes or shapes, and for other purposes such as regulating (or measuring) fluid flow. These fittings are used in plumbing to manipulat ...
s, to be dezincification-resistant.
Use in musical instruments
![Trumpets02262006](https://upload.wikimedia.org/wikipedia/commons/5/5d/Trumpets02262006.jpg)
The high
malleability and workability, relatively good resistance to
corrosion
Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engi ...
, and traditionally attributed
acoustic properties of brass, have made it the usual metal of choice for construction of
musical instruments whose acoustic
resonator
A resonator is a device or system that exhibits resonance or resonant behavior. That is, it naturally oscillates with greater amplitude at some frequencies, called resonant frequencies, than at other frequencies. The oscillations in a resonator ...
s consist of long, relatively narrow tubing, often folded or coiled for compactness;
silver
Silver is a chemical element with the symbol Ag (from the Latin ', derived from the Proto-Indo-European ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical ...
and its alloys, and even
gold
Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile me ...
, have been used for the same reasons, but brass is the most economical choice. Collectively known as
brass instruments, these include the
trombone
The trombone (german: Posaune, Italian, French: ''trombone'') is a musical instrument in the brass family. As with all brass instruments, sound is produced when the player's vibrating lips cause the air column inside the instrument to vibrate ...
,
tuba
The tuba (; ) is the lowest-pitched musical instrument in the brass family. As with all brass instruments, the sound is produced by lip vibrationa buzzinto a mouthpiece. It first appeared in the mid-19th century, making it one of the ne ...
,
trumpet
The trumpet is a brass instrument commonly used in classical and jazz ensembles. The trumpet group ranges from the piccolo trumpet—with the highest register in the brass family—to the bass trumpet, pitched one octave below the standard ...
,
cornet,
flugelhorn,
baritone horn,
euphonium
The euphonium is a medium-sized, 3 or 4-valve, often compensating, conical-bore, tenor-voiced brass instrument that derives its name from the Ancient Greek word ''euphōnos'', meaning "well-sounding" or "sweet-voiced" ( ''eu'' means "well" o ...
,
tenor horn
The tenor horn (British English; alto horn in American English, Althorn in Germany; occasionally referred to as E horn) is a brass instrument in the saxhorn family and is usually pitched in E. It has a bore that is mostly conical, like the flug ...
, and
French horn
The French horn (since the 1930s known simply as the horn in professional music circles) is a brass instrument made of tubing wrapped into a coil with a flared bell. The double horn in F/B (technically a variety of German horn) is the horn most ...
, and many other "
horn
Horn most often refers to:
*Horn (acoustic), a conical or bell shaped aperture used to guide sound
** Horn (instrument), collective name for tube-shaped wind musical instruments
*Horn (anatomy), a pointed, bony projection on the head of various ...
s", many in variously-sized families, such as the
saxhorns
The saxhorn is a family of valved brass instruments that have conical bores and deep cup-shaped mouthpieces. The saxhorn family was developed by Adolphe Sax, who is also known for creating the saxophone family. The sound of the saxhorn has a ...
.
Other
wind instrument
A wind instrument is a musical instrument that contains some type of resonator (usually a tube) in which a column of air is set into vibration by the player blowing into (or over) a mouthpiece set at or near the end of the resonator. The pitc ...
s may be constructed of brass or other metals, and indeed most modern student-model
flutes and
piccolos are made of some variety of brass, usually a
cupronickel
Cupronickel or copper-nickel (CuNi) is an alloy of copper that contains nickel and strengthening elements, such as iron and manganese. The copper content typically varies from 60 to 90 percent. (Monel is a nickel-copper alloy that contains a minimu ...
alloy
An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductilit ...
similar to
nickel silver (also known as German silver).
Clarinets
The clarinet is a musical instrument in the woodwind family. The instrument has a nearly cylindrical bore and a flared bell, and uses a single reed to produce sound.
Clarinets comprise a family of instruments of differing sizes and pitches. ...
, especially low clarinets such as the
contrabass and
subcontrabass, are sometimes made of metal because of limited supplies of the dense, fine-grained tropical hardwoods traditionally preferred for smaller
woodwind
Woodwind instruments are a family of musical instruments within the greater category of wind instruments. Common examples include flute, clarinet, oboe, bassoon, and saxophone. There are two main types of woodwind instruments: flutes and re ...
s. For the same reason, some low clarinets,
bassoons and
contrabassoons feature a hybrid construction, with long, straight sections of wood, and curved joints, neck, and/or bell of metal. The use of metal also avoids the risks of exposing wooden instruments to changes in temperature or humidity, which can cause sudden cracking. Even though the
saxophone
The saxophone (often referred to colloquially as the sax) is a type of Single-reed instrument, single-reed woodwind instrument with a conical body, usually made of brass. As with all single-reed instruments, sound is produced when a reed (mouthpi ...
s and
sarrusophone
The sarrusophones are a family of metal double reed conical bore woodwind instruments patented and first manufactured by Pierre-Louis Gautrot in 1856. Gautrot named the sarrusophone after French bandmaster Pierre-Auguste Sarrus (1813–1876), ...
s are classified as woodwind instruments, they are normally made of brass for similar reasons, and because their wide, conical bores and thin-walled bodies are more easily and efficiently made by forming sheet metal than by machining wood.
The keywork of most modern woodwinds, including wooden-bodied instruments, is also usually made of an alloy such as nickel silver. Such alloys are stiffer and more durable than the brass used to construct the instrument bodies, but still workable with simple hand tools—a boon to quick repairs. The
mouthpieces of both brass instruments and, less commonly, woodwind instruments are often made of brass among other metals as well.
Next to the brass instruments, the most notable use of brass in music is in various
percussion instrument
A percussion instrument is a musical instrument that is sounded by being struck or scraped by a beater including attached or enclosed beaters or rattles struck, scraped or rubbed by hand or struck against another similar instrument. Ex ...
s, most notably
cymbals,
gong
A gongFrom Indonesian and ms, gong; jv, ꦒꦺꦴꦁ ; zh, c=鑼, p=luó; ja, , dora; km, គង ; th, ฆ้อง ; vi, cồng chiêng; as, কাঁহ is a percussion instrument originating in East Asia and Southeast Asia. Gongs ...
s, and
orchestral (tubular) bells (large "church"
bell
A bell is a directly struck idiophone percussion instrument. Most bells have the shape of a hollow cup that when struck vibrates in a single strong strike tone, with its sides forming an efficient resonator. The strike may be made by an inte ...
s are normally made of
bronze). Small
handbell
A handbell is a bell designed to be rung by hand. To ring a handbell, a ringer grasps the bell by its slightly flexible handle – traditionally made of leather, but often now made of plastic – and moves the arm to make the hinged cla ...
s and "
jingle bell
A jingle bell or sleigh bell is a type of bell which produces a distinctive 'jingle' sound, especially in large numbers. They find use in many areas as a percussion instrument, including the classic sleigh bell sound and morris dancing. T ...
s" are also commonly made of brass.
The
harmonica is a
free reed aerophone
A free reed aerophone is a musical instrument that produces sound as air flows past a vibrating reed in a frame. Air pressure is typically generated by breath or with a bellows. In the Hornbostel–Sachs system, it is number: 412.13 (a member ...
, also often made from brass. In
organ pipes of the reed family, brass strips (called tongues) are used as the reeds, which beat against the
shallot
The shallot is a botanical variety (a cultivar) of the onion. Until 2010, the (French red) shallot was classified as a separate species, ''Allium ascalonicum''. The taxon was synonymized with '' Allium cepa'' (the common onion) in 2010, as the ...
(or beat "through" the shallot in the case of a "free" reed). Although not part of the brass section,
snare drums are also sometimes made of brass. Some parts on
electric guitars
An electric guitar is a guitar that requires external amplification in order to be heard at typical performance volumes, unlike a standard acoustic guitar (however combinations of the two - a semi-acoustic guitar and an electric acoustic gu ...
are also made from brass, especially inertia blocks on tremolo systems for its tonal properties, and for string nuts and saddles for both tonal properties and its low friction.
Germicidal and antimicrobial applications
The
bactericidal properties of brass have been observed for centuries, particularly in marine environments where it prevents
biofouling
Biofouling or biological fouling is the accumulation of microorganisms, plants, algae, or small animals where it is not wanted on surfaces such as ship and submarine hulls, devices such as water inlets, pipework, grates, ponds, and rivers that ...
. Depending upon the type and concentration of
pathogen
In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ ...
s and the medium they are in, brass kills these
microorganism
A microorganism, or microbe,, ''mikros'', "small") and ''organism'' from the el, ὀργανισμός, ''organismós'', "organism"). It is usually written as a single word but is sometimes hyphenated (''micro-organism''), especially in olde ...
s within a few minutes to hours of contact.
[
A large number of independent studies][ confirm this antimicrobial effect, even against antibiotic-resistant bacteria such as MRSA and VRSA. The mechanisms of antimicrobial action by copper and its alloys, including brass, are a subject of intense and ongoing investigation.][
]
Season cracking
Brass is susceptible to stress corrosion cracking, especially from ammonia
Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous wa ...
or substances containing or releasing ammonia. The problem is sometimes known as season cracking
Season cracking is a form of stress-corrosion cracking of brass cartridge cases originally reported from British forces in India. During the monsoon season, military activity was temporarily reduced, and ammunition was stored in stables until the ...
after it was first discovered in brass cartridge
Cartridge may refer to:
Objects
* Cartridge (firearms), a type of modern ammunition
* ROM cartridge, a removable component in an electronic device
* Cartridge (respirator), a type of filter used in respirators
Other uses
* Cartridge (surname), a ...
s used for rifle ammunition during the 1920s in the British Indian Army. The problem was caused by high residual stress
In materials science and solid mechanics, residual stresses are stresses that remain in a solid material after the original cause of the stresses has been removed. Residual stress may be desirable or undesirable. For example, laser peening i ...
es from cold forming of the cases during manufacture, together with chemical attack from traces of ammonia in the atmosphere. The cartridges were stored in stables and the ammonia concentration rose during the hot summer months, thus initiating brittle cracks. The problem was resolved by annealing the cases, and storing the cartridges elsewhere.
Types
Other phases than α, β and γ are ε, a hexagonal intermetallic CuZn3, and η, a solid solution of copper in zinc.
History
Although forms of brass have been in use since prehistory
Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use ...
, its true nature as a copper-zinc alloy was not understood until the post-medieval period because the zinc vapor
In physics, a vapor (American English) or vapour (British English and Canadian English; see spelling differences) is a substance in the gas phase at a temperature lower than its critical temperature,R. H. Petrucci, W. S. Harwood, and F. G. Her ...
which reacted with copper to make brass was not recognized as a metal
A metal (from Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typicall ...
. The King James Bible makes many references to "brass" to translate "nechosheth" (bronze or copper) from Hebrew to English. The earliest brasses may have been natural alloys made by smelting
Smelting is a process of applying heat to ore, to extract a base metal. It is a form of extractive metallurgy. It is used to extract many metals from their ores, including silver, iron, copper, and other base metals. Smelting uses heat and a ...
zinc-rich copper ore
Ore is natural rock or sediment that contains one or more valuable minerals, typically containing metals, that can be mined, treated and sold at a profit.Encyclopædia Britannica. "Ore". Encyclopædia Britannica Online. Retrieved 7 Apr ...
s.[Craddock, P. T. and Eckstein, K (2003) "Production of Brass in Antiquity by Direct Reduction" in Craddock, P. T. and Lang, J. (eds.) ''Mining and Metal Production Through the Ages''. London: British Museum, pp. 226–27] By the Roman
Roman or Romans most often refers to:
*Rome, the capital city of Italy
*Ancient Rome, Roman civilization from 8th century BC to 5th century AD
*Roman people, the people of ancient Rome
*'' Epistle to the Romans'', shortened to ''Romans'', a lette ...
period brass was being deliberately produced from metallic copper and zinc minerals using the cementation process, the product of which was calamine brass Calamine brass is brass produced by a particular alloying technique using the zinc ore calamine directly, rather than first refining it to metallic zinc. Direct zinc smelting appears to have been unknown in Europe until the mid-18th century, even th ...
, and variations on this method continued until the mid-19th century. It was eventually replaced by spelter
Spelter is a zinc–lead alloy that ages to resemble bronze, but is softer and has a lower melting point. The name can also refer to a copper–zinc alloy (a brass) used for brazing, or to pure zinc.
Etymology
In his etymology of the English ...
ing, the direct alloying of copper and zinc metal which was introduced to Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...
in the 16th century.[
Brass has sometimes historically been referred to as "yellow copper".
]
Early copper-zinc alloys
In West Asia
Western Asia, West Asia, or Southwest Asia, is the westernmost subregion of the larger geographical region of Asia, as defined by some academics, UN bodies and other institutions. It is almost entirely a part of the Middle East, and includes Ana ...
and the Eastern Mediterranean early copper-zinc alloys are now known in small numbers from a number of 3rd millennium BC sites in the Aegean, Iraq
Iraq,; ku, عێراق, translit=Êraq officially the Republic of Iraq, '; ku, کۆماری عێراق, translit=Komarî Êraq is a country in Western Asia. It is bordered by Turkey to the north, Iran to the east, the Persian Gulf and K ...
, the United Arab Emirates
The United Arab Emirates (UAE; ar, اَلْإِمَارَات الْعَرَبِيَة الْمُتَحِدَة ), or simply the Emirates ( ar, الِْإمَارَات ), is a country in Western Asia ( The Middle East). It is located at t ...
, Kalmykia, Turkmenistan
Turkmenistan ( or ; tk, Türkmenistan / Түркменистан, ) is a country located in Central Asia, bordered by Kazakhstan to the northwest, Uzbekistan to the north, east and northeast, Afghanistan to the southeast, Iran to the sout ...
and Georgia
Georgia most commonly refers to:
* Georgia (country), a country in the Caucasus region of Eurasia
* Georgia (U.S. state), a state in the Southeast United States
Georgia may also refer to:
Places
Historical states and entities
* Related to the ...
and from 2nd millennium BC sites in West India
Western India is a loosely defined region of India consisting of its western part. The Ministry of Home Affairs in its Western Zonal Council Administrative division includes the states of Goa, Gujarat, and Maharashtra along with the Unio ...
, Uzbekistan
Uzbekistan (, ; uz, Ozbekiston, italic=yes / , ; russian: Узбекистан), officially the Republic of Uzbekistan ( uz, Ozbekiston Respublikasi, italic=yes / ; russian: Республика Узбекистан), is a doubly landlocked co ...
, Iran
Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...
, Syria, Iraq and Canaan
Canaan (; Phoenician: 𐤊𐤍𐤏𐤍 – ; he, כְּנַעַן – , in pausa – ; grc-bib, Χανααν – ;The current scholarly edition of the Greek Old Testament spells the word without any accents, cf. Septuaginta : id est Vetus T ...
. Isolated examples of copper-zinc alloy
An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductilit ...
s are known in China from the 1st century AD, long after bronze was widely used.[
The compositions of these early "brass" objects are highly variable and most have zinc contents of between 5% and 15% wt which is lower than in brass produced by cementation.][Craddock and Eckstein 2003 p. 217] These may be "natural alloys" manufactured by smelting zinc rich copper ores in redox
Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a ...
conditions. Many have similar tin contents to contemporary bronze artefacts and it is possible that some copper-zinc alloys were accidental and perhaps not even distinguished from copper. However the large number of copper-zinc alloys now known suggests that at least some were deliberately manufactured and many have zinc contents of more than 12% wt which would have resulted in a distinctive golden color.
By the 8th–7th century BC Assyria
Assyria ( Neo-Assyrian cuneiform: , romanized: ''māt Aššur''; syc, ܐܬܘܪ, ʾāthor) was a major ancient Mesopotamian civilization which existed as a city-state at times controlling regional territories in the indigenous lands of the ...
n cuneiform
Cuneiform is a logo-syllabic script that was used to write several languages of the Ancient Middle East. The script was in active use from the early Bronze Age until the beginning of the Common Era. It is named for the characteristic wedge-sh ...
tablets mention the exploitation of the "copper of the mountains" and this may refer to "natural" brass. "Oreikhalkon" (mountain copper), the Ancient Greek
Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...
translation of this term, was later adapted to the Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
'' aurichalcum'' meaning "golden copper" which became the standard term for brass. In the 4th century BC Plato
Plato ( ; grc-gre, Πλάτων ; 428/427 or 424/423 – 348/347 BC) was a Greek philosopher born in Athens during the Classical period in Ancient Greece. He founded the Platonist school of thought and the Academy, the first institution ...
knew ''orichalkos'' as rare and nearly as valuable as gold[ and ]Pliny
Pliny may refer to:
People
* Pliny the Elder (23–79 CE), ancient Roman nobleman, scientist, historian, and author of ''Naturalis Historia'' (''Pliny's Natural History'')
* Pliny the Younger (died 113), ancient Roman statesman, orator, w ...
describes how ''aurichalcum'' had come from Cypriot
Cypriot (in older sources often "Cypriote") refers to someone or something of, from, or related to the country of Cyprus.
* Cypriot people, or of Cypriot descent; this includes:
**Armenian Cypriots
**Greek Cypriots
**Maronite Cypriots
**Turkish C ...
ore deposits which had been exhausted by the 1st century AD. X-ray fluorescence
X-ray fluorescence (XRF) is the emission of characteristic "secondary" (or fluorescent) X-rays from a material that has been excited by being bombarded with high-energy X-rays or gamma rays. The phenomenon is widely used for elemental analysis ...
analysis of 39 orichalcum
Orichalcum or aurichalcum is a metal mentioned in several ancient writings, including the story of Atlantis in the '' Critias'' of Plato. Within the dialogue, Critias (460–403 BC) claims that orichalcum had been considered second only to g ...
ingots recovered from a 2,600-year-old shipwreck off Sicily found them to be an alloy made with 75–80% copper, 15–20% zinc and small percentages of nickel, lead and iron.
Roman world
During the later part of first millennium BC the use of brass spread across a wide geographical area from Britain
Britain most often refers to:
* The United Kingdom, a sovereign state in Europe comprising the island of Great Britain, the north-eastern part of the island of Ireland and many smaller islands
* Great Britain, the largest island in the United King ...
and Spain
, image_flag = Bandera de España.svg
, image_coat = Escudo de España (mazonado).svg
, national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond")
, national_anthem = (English: "Royal March")
, i ...
[ in the west to ]Iran
Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...
, and India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
in the east. This seems to have been encouraged by exports and influence from the Middle East
The Middle East ( ar, الشرق الأوسط, ISO 233: ) is a geopolitical region commonly encompassing Arabia (including the Arabian Peninsula and Bahrain), Asia Minor (Asian part of Turkey except Hatay Province), East Thrace (Europ ...
and eastern Mediterranean where deliberate production of brass from metallic copper and zinc ores had been introduced. The 4th century BC writer Theopompus
Theopompus ( grc-gre, Θεόπομπος, ''Theópompos''; c. 380 BCc. 315 BC) was an ancient Greek historian and rhetorician.
Biography
Theopompus was born on the Aegean island of Chios. In early youth, he seems to have spent some time at Athen ...
, quoted by Strabo, describes how heating earth from Andeira in Turkey
Turkey ( tr, Türkiye ), officially the Republic of Türkiye ( tr, Türkiye Cumhuriyeti, links=no ), is a transcontinental country located mainly on the Anatolian Peninsula in Western Asia, with a small portion on the Balkan Peninsula in ...
produced "droplets of false silver", probably metallic zinc, which could be used to turn copper into oreichalkos. In the 1st century BC the Greek Dioscorides
Pedanius Dioscorides ( grc-gre, Πεδάνιος Διοσκουρίδης, ; 40–90 AD), “the father of pharmacognosy”, was a Greek physician, pharmacologist, botanist, and author of '' De materia medica'' (, On Medical Material) —a 5-vo ...
seems to have recognized a link between zinc mineral
In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2 ...
s and brass describing how Cadmia In alchemy, cadmia (Latin for cadmium) is an oxide of zinc (tutty; from ar, توتيا ''tutiya'', via Persian, from Sanskrit तुत्थ ''tuttha'') which collects on the sides of furnaces where copper or brass was smelted, and zinc sublimed. ...
(zinc oxide
Zinc oxide is an inorganic compound with the formula . It is a white powder that is insoluble in water. ZnO is used as an additive in numerous materials and products including cosmetics, food supplements, rubbers, plastics, ceramics, glass, cement ...
) was found on the walls of furnace
A furnace is a structure in which heat is produced with the help of combustion.
Furnace may also refer to:
Appliances Buildings
* Furnace (central heating): a furnace , or a heater or boiler , used to generate heat for buildings
* Boiler, used t ...
s used to heat either zinc ore or copper and explaining that it can then be used to make brass.
By the first century BC brass was available in sufficient supply to use as coin
A coin is a small, flat (usually depending on the country or value), round piece of metal or plastic used primarily as a medium of exchange or legal tender. They are standardized in weight, and produced in large quantities at a mint in order t ...
age in Phrygia and Bithynia,[ and after the Augustan currency reform of 23 BC it was also used to make Roman '' dupondii'' and '']sestertii
The ''sestertius'' (plural ''sestertii''), or sesterce (plural sesterces), was an ancient Roman coin. During the Roman Republic it was a small, silver coin issued only on rare occasions. During the Roman Empire it was a large brass coin.
The n ...
''.[ The uniform use of brass for coinage and military equipment across the ]Roman world
The culture of ancient Rome existed throughout the almost 1200-year history of the civilization of Ancient Rome. The term refers to the culture of the Roman Republic, later the Roman Empire, which at its peak covered an area from present-day Lo ...
may indicate a degree of state involvement in the industry,[ and brass even seems to have been deliberately boycotted by ]Jewish
Jews ( he, יְהוּדִים, , ) or Jewish people are an ethnoreligious group and nation originating from the Israelites Israelite origins and kingdom: "The first act in the long drama of Jewish history is the age of the Israelites""The ...
communities in Palestine because of its association with Roman authority.[
Brass was produced by the cementation process where copper and zinc ore are heated together until zinc vapor is produced which reacts with the copper. There is good archaeological evidence for this process and ]crucible
A crucible is a ceramic or metal container in which metals or other substances may be melted or subjected to very high temperatures. While crucibles were historically usually made from clay, they can be made from any material that withstands te ...
s used to produce brass by cementation have been found on Roman period sites including Xanten
Xanten (, Low Rhenish: ''Santen'') is a town in the state of North Rhine-Westphalia, Germany. It is located in the district of Wesel.
Xanten is known for the Archaeological Park, one of the largest archaeological open air museums in the wo ...
[ and Nidda][ in ]Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...
, Lyon
Lyon,, ; Occitan language, Occitan: ''Lion'', hist. ''Lionés'' also spelled in English as Lyons, is the List of communes in France with over 20,000 inhabitants, third-largest city and Urban area (France), second-largest metropolitan area of F ...
in France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan area ...
[Rehren and Martinon Torres 2008, pp. 170–71] and at a number of sites in Britain. They vary in size from tiny acorn sized to large amphorae like vessels but all have elevated levels of zinc on the interior and are lidded. They show no signs of slag or metal prills
A prill is a small aggregate or globule of a material, most often a dry sphere, formed from a melted liquid through spray crystallization. Prilled is a term used in mining and manufacturing to refer to a product that has been pelletized. ANFO ex ...
suggesting that zinc minerals were heated to produce zinc vapor which reacted with metallic copper in a solid state reaction. The fabric of these crucibles is porous, probably designed to prevent a buildup of pressure, and many have small holes in the lids which may be designed to release pressure or to add additional zinc minerals near the end of the process. Dioscorides mentioned that zinc minerals were used for both the working and finishing of brass, perhaps suggesting secondary additions.[Craddock and Eckstein 2003, p. 224]
Brass made during the early Roman period seems to have varied between 20% and 28% wt zinc.[ The high content of zinc in coinage and brass objects declined after the first century AD and it has been suggested that this reflects zinc loss during ]recycling
Recycling is the process of converting waste materials into new materials and objects. The recovery of energy from waste materials is often included in this concept. The recyclability of a material depends on its ability to reacquire the p ...
and thus an interruption in the production of new brass.[ However it is now thought this was probably a deliberate change in composition][ and overall the use of brass increases over this period making up around 40% of all ]copper alloys
Copper alloys are metal alloys that have copper as their principal component. They have high resistance against corrosion. The best known traditional types are bronze, where tin is a significant addition, and brass, using zinc instead. Both of ...
used in the Roman world by the 4th century AD.
Medieval period
Little is known about the production of brass during the centuries immediately after the collapse of the Roman Empire
The Roman Empire ( la, Imperium Romanum ; grc-gre, Βασιλεία τῶν Ῥωμαίων, Basileía tôn Rhōmaíōn) was the post- Republican period of ancient Rome. As a polity, it included large territorial holdings around the Mediter ...
. Disruption in the trade of tin for bronze from Western Europe
Western Europe is the western region of Europe. The region's countries and territories vary depending on context.
The concept of "the West" appeared in Europe in juxtaposition to "the East" and originally applied to the ancient Mediterranean ...
may have contributed to the increasing popularity of brass in the east and by the 6th–7th centuries AD over 90% of copper alloy
Copper alloys are metal alloys that have copper as their principal component. They have high resistance against corrosion. The best known traditional types are bronze, where tin is a significant addition, and brass, using zinc instead. Both of t ...
artefacts from Egypt
Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a transcontinental country spanning the northeast corner of Africa and southwest corner of Asia via a land bridge formed by the Sinai Peninsula. It is bordered by the Medit ...
were made of brass. However other alloys such as low tin bronze were also used and they vary depending on local cultural attitudes, the purpose of the metal and access to zinc, especially between the Islamic and Byzantine
The Byzantine Empire, also referred to as the Eastern Roman Empire or Byzantium, was the continuation of the Roman Empire primarily in its eastern provinces during Late Antiquity and the Middle Ages, when its capital city was Constantinopl ...
world.[ Conversely the use of true brass seems to have declined in Western Europe during this period in favor of ]gunmetal
Gun metal, also known as red brass in the United States, is a type of bronze; an alloy of copper, tin and zinc. Proportions vary but 88% copper, 8–10% tin, and 2–4% zinc is an approximation. Originally used chiefly for making guns, it has ...
s and other mixed alloys but by about 1000 brass artefacts are found in Scandinavia
Scandinavia; Sámi languages: /. ( ) is a subregion in Northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. In English usage, ''Scandinavia'' most commonly refers to Denmark, Norway, and Swe ...
n graves in Scotland
Scotland (, ) is a Countries of the United Kingdom, country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a Anglo-Scottish border, border with England to the southeast ...
,[ brass was being used in the manufacture of coins in ]Northumbria
la, Regnum Northanhymbrorum
, conventional_long_name = Kingdom of Northumbria
, common_name = Northumbria
, status = State
, status_text = Unified Anglian kingdom (before 876)North: Anglian kingdom (af ...
and there is archaeological and historical evidence for the production of calamine brass Calamine brass is brass produced by a particular alloying technique using the zinc ore calamine directly, rather than first refining it to metallic zinc. Direct zinc smelting appears to have been unknown in Europe until the mid-18th century, even th ...
in Germany and the Low Countries
The term Low Countries, also known as the Low Lands ( nl, de Lage Landen, french: les Pays-Bas, lb, déi Niddereg Lännereien) and historically called the Netherlands ( nl, de Nederlanden), Flanders, or Belgica, is a coastal lowland region in N ...
, areas rich in calamine
Calamine, also known as calamine lotion, is a medication used to treat mild itchiness. This includes from sunburn, insect bites, poison ivy, poison oak, and other mild skin conditions. It may also help dry out skin irritation. It is applie ...
ore.
These places would remain important centers of brass making throughout the medieval
In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire ...
period, especially Dinant. Brass objects are still collectively known as ''dinanderie'' in French. The baptismal font at St Bartholomew's Church, Liège in modern Belgium
Belgium, ; french: Belgique ; german: Belgien officially the Kingdom of Belgium, is a country in Northwestern Europe. The country is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeast, France to th ...
(before 1117) is an outstanding masterpiece of Romanesque brass casting, though also often described as bronze. The metal of the early 12th-century Gloucester Candlestick
The Gloucester Candlestick is an elaborately decorated English Romanesque gilt-bronze candlestick, now in the Victoria and Albert Museum in London. It was made for Gloucester Cathedral between 1104 and 1113, and is one of the outstanding surviv ...
is unusual even by medieval standards in being a mixture of copper, zinc, tin, lead, nickel
Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow ...
, iron, antimony
Antimony is a chemical element with the symbol Sb (from la, stibium) and atomic number 51. A lustrous gray metalloid, it is found in nature mainly as the sulfide mineral stibnite (Sb2S3). Antimony compounds have been known since ancient t ...
and arsenic
Arsenic is a chemical element with the symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, ...
with an unusually large amount of silver
Silver is a chemical element with the symbol Ag (from the Latin ', derived from the Proto-Indo-European ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical ...
, ranging from 22.5% in the base to 5.76% in the pan below the candle. The proportions of this mixture may suggest that the candlestick was made from a hoard of old coins, probably Late Roman. Latten
Historically, the term "latten" referred loosely to the copper alloys such as brass
or bronze
that appeared in the Middle Ages and through to the late-18th and early-19th centuries. Such alloys were used for monumental brasses, in decorative effect ...
is a term for decorative borders and similar objects cut from sheet metal, whether of brass or bronze. Aquamanile
In modern usage, an aquamanile (plural aquamanilia or simply aquamaniles) is a ewer or jug-type vessel in the form of one or more animal or human figures. It usually contained water for the washing of hands (''aqua'' + ''manos'') over a basin, ...
s were typically made in brass in both the European and Islamic worlds.
The cementation process continued to be used but literary sources from both Europe and the Islamic world seem to describe variants of a higher temperature liquid process which took place in open-topped crucibles. Islamic cementation seems to have used zinc oxide known as ''tutiya'' or tutty In alchemy, cadmia (Latin for cadmium) is an oxide of zinc (tutty; from ar, توتيا ''tutiya'', via Persian, from Sanskrit तुत्थ ''tuttha'') which collects on the sides of furnaces where copper or brass was smelted, and zinc sublimed. ...
rather than zinc ores for brass-making, resulting in a metal with lower iron
Iron () is a chemical element with Symbol (chemistry), symbol Fe (from la, Wikt:ferrum, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 element, group 8 of the periodic table. It is, Abundanc ...
impurities. A number of Islamic writers and the 13th century Italian
Italian(s) may refer to:
* Anything of, from, or related to the people of Italy over the centuries
** Italians, an ethnic group or simply a citizen of the Italian Republic or Italian Kingdom
** Italian language, a Romance language
*** Regional Ita ...
Marco Polo describe how this was obtained by sublimation from zinc ores and condensed onto clay
Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4).
Clays develop plasticity when wet, due to a molecular film of water surrounding the clay par ...
or iron bars, archaeological examples of which have been identified at Kush
Kush or Cush may refer to:
Bible
* Cush (Bible), two people and one or more places in the Hebrew Bible
Places
* Kush (mountain), a mountain near Kalat, Pakistan Balochistan
* Kush (satrapy), a satrapy of the Achaemenid Empire
* Hindu Kush, a ...
in Iran. It could then be used for brass making or medicinal purposes. In 10th century Yemen
Yemen (; ar, ٱلْيَمَن, al-Yaman), officially the Republic of Yemen,, ) is a country in Western Asia. It is situated on the southern end of the Arabian Peninsula, and borders Saudi Arabia to the Saudi Arabia–Yemen border, north and ...
al-Hamdani described how spreading al-iglimiya, probably zinc oxide, onto the surface of molten copper produced tutiya vapor which then reacted with the metal. The 13th century Iranian writer al-Kashani describes a more complex process whereby ''tutiya'' was mixed with raisin
A raisin is a dried grape. Raisins are produced in many regions of the world and may be eaten raw or used in cooking, baking, and brewing. In the United Kingdom, Ireland, New Zealand, and Australia, the word ''raisin'' is reserved for the ...
s and gently roasted before being added to the surface of the molten metal. A temporary lid was added at this point presumably to minimize the escape of zinc vapor.
In Europe a similar liquid process in open-topped crucibles took place which was probably less efficient than the Roman process and the use of the term tutty by Albertus Magnus
Albertus Magnus (c. 1200 – 15 November 1280), also known as Saint Albert the Great or Albert of Cologne, was a German Dominican friar, philosopher, scientist, and bishop. Later canonised as a Catholic saint, he was known during his li ...
in the 13th century suggests influence from Islamic technology. The 12th century German
German(s) may refer to:
* Germany (of or related to)
** Germania (historical use)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizens of Germany, see also German nationality law
**Ge ...
monk Theophilus
Theophilus is a male given name with a range of alternative spellings. Its origin is the Greek word Θεόφιλος from θεός (God) and φιλία (love or affection) can be translated as "Love of God" or "Friend of God", i.e., it is a theoph ...
described how preheated crucibles were one sixth filled with powdered calamine and charcoal then topped up with copper and charcoal before being melted, stirred then filled again. The final product was cast
Cast may refer to:
Music
* Cast (band), an English alternative rock band
* Cast (Mexican band), a progressive Mexican rock band
* The Cast, a Scottish musical duo: Mairi Campbell and Dave Francis
* ''Cast'', a 2012 album by Trespassers William
...
, then again melted with calamine. It has been suggested that this second melting may have taken place at a lower temperature to allow more zinc to be absorbed. Albertus Magnus noted that the "power" of both calamine and tutty could evaporate and described how the addition of powdered glass
Glass is a non-crystalline, often transparent, amorphous solid that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by rapid cooling ( quenching ...
could create a film to bind it to the metal.
German brass making crucibles are known from Dortmund dating to the 10th century AD and from Soest and Schwerte
Schwerte ( Westphalian: ''Schweierte'') is a town in the district of Unna, in North Rhine-Westphalia, Germany.
Geography
Schwerte is situated in the Ruhr valley, at the south-east border of the Ruhr Area. South of Schwerte begins the mountainous ...
in Westphalia
Westphalia (; german: Westfalen ; nds, Westfalen ) is a region of northwestern Germany and one of the three historic parts of the state of North Rhine-Westphalia. It has an area of and 7.9 million inhabitants.
The territory of the regio ...
dating to around the 13th century confirm Theophilus' account, as they are open-topped, although ceramic
A ceramic is any of the various hard, brittle, heat-resistant and corrosion-resistant materials made by shaping and then firing an inorganic, nonmetallic material, such as clay, at a high temperature. Common examples are earthenware, porcelain ...
discs from Soest may have served as loose lids which may have been used to reduce zinc evaporation, and have slag on the interior resulting from a liquid process.
Africa
Some of the most famous objects in African art
African art describes the modern and historical paintings, sculptures, installations, and other visual culture from native or indigenous Ethnic groups of Africa, Africans and the African continent. The definition may also include the art of the ...
are the lost wax
Lost-wax casting (also called "investment casting", "precision casting", or ''cire perdue'' which has been adopted into English from the French, ) is the process by which a duplicate metal sculpture (often silver, gold, brass, or bronze) is ...
castings of West Africa, mostly from what is now Nigeria
Nigeria ( ), , ig, Naìjíríyà, yo, Nàìjíríà, pcm, Naijá , ff, Naajeeriya, kcg, Naijeriya officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf o ...
, produced first by the Kingdom of Ife and then the Benin Empire. Though normally described as "bronzes", the Benin Bronzes
The Benin Bronzes are a group of several thousand metal plaques and sculptures that decorated the royal palace of the Kingdom of Benin, in what is now Edo State, Nigeria. Collectively, the objects form the best examples of Benin art and were cr ...
, now mostly in the British Museum
The British Museum is a public museum dedicated to human history, art and culture located in the Bloomsbury area of London. Its permanent collection of eight million works is among the largest and most comprehensive in existence. It docum ...
and other Western collections, and the large portrait heads such as the Bronze Head from Ife
The Bronze Head from Ife, or Ife Head, is one of eighteen copper alloy sculptures that were unearthed in 1938 at Ife in Nigeria, the religious and former royal centre of the Yoruba people. It is believed to represent a king. It was probably ma ...
of "heavily leaded zinc-brass" and the Bronze Head of Queen Idia
The Bronze Head of Queen Idia is a commemorative bronze head from the medieval Kingdom of Benin in West Africa that probably represents Idia, mother of Oba Esigie, made during the early sixteenth century at the Benin court. Many Benin works of a ...
, both also British Museum, are better described as brass, though of variable compositions. Work in brass or bronze continued to be important in Benin art
Benin art is the art from the Kingdom of Benin or Edo Empire (1440–1897), a pre-colonial African state located in what is now known as the Southern region of Nigeria. Primarily made of cast bronze and carved ivory, Benin art was produced mai ...
and other West African traditions such as Akan goldweights
Akan goldweights (locally known as mrammou) are weights made of brass used as a measuring system by the Akan people of West Africa, particularly for wei and fair-trade arrangements with one another. The status of a man increased significantly if ...
, where the metal was regarded as a more valuable material than in Europe.
Renaissance and post-medieval Europe
The Renaissance
The Renaissance ( , ) , from , with the same meanings. is a period in European history
The history of Europe is traditionally divided into four time periods: prehistoric Europe (prior to about 800 BC), classical antiquity (800 BC to AD ...
saw important changes to both the theory and practice of brassmaking in Europe. By the 15th century there is evidence for the renewed use of lidded cementation crucibles at Zwickau
Zwickau (; is, with around 87,500 inhabitants (2020), the fourth-largest city of Saxony after Leipzig, Dresden and Chemnitz and it is the seat of the Zwickau District. The West Saxon city is situated in the valley of the Zwickau Mulde (German: ...
in Germany. These large crucibles were capable of producing c.20 kg of brass. There are traces of slag and pieces of metal on the interior. Their irregular composition suggests that this was a lower temperature, not entirely liquid, process. The crucible lids had small holes which were blocked with clay plugs near the end of the process presumably to maximize zinc absorption in the final stages. Triangular crucibles were then used to melt the brass for casting
Casting is a manufacturing process in which a liquid material is usually poured into a mold, which contains a hollow cavity of the desired shape, and then allowed to solidify. The solidified part is also known as a ''casting'', which is ejected ...
.
16th-century technical writers such as Biringuccio, Ercker and Agricola
Agricola, the Latin word for farmer, may also refer to:
People Cognomen or given name
:''In chronological order''
* Gnaeus Julius Agricola (40–93), Roman governor of Britannia (AD 77–85)
* Sextus Calpurnius Agricola, Roman governor of the mi ...
described a variety of cementation brass making techniques and came closer to understanding the true nature of the process noting that copper became heavier as it changed to brass and that it became more golden as additional calamine was added. Zinc metal was also becoming more commonplace. By 1513 metallic zinc ingot
An ingot is a piece of relatively pure material, usually metal, that is cast into a shape suitable for further processing. In steelmaking, it is the first step among semi-finished casting products. Ingots usually require a second procedure of sha ...
s from India and China were arriving in London
London is the capital and List of urban areas in the United Kingdom, largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a estuary dow ...
and pellets of zinc condensed in furnace
A furnace is a structure in which heat is produced with the help of combustion.
Furnace may also refer to:
Appliances Buildings
* Furnace (central heating): a furnace , or a heater or boiler , used to generate heat for buildings
* Boiler, used t ...
flues at the Rammelsberg
The Rammelsberg is a mountain, high, on the northern edge of the Harz range, south of the historic town of Goslar in the North German state of Lower Saxony. The mountain is the location of an important silver, copper, and lead mine, the only min ...
in Germany were exploited for cementation brass making from around 1550.
Eventually it was discovered that metallic zinc could be alloy
An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductilit ...
ed with copper to make brass, a process known as speltering,[Craddock and Eckstein 2003, 228] and by 1657 the German chemist Johann Glauber
Johann Rudolf Glauber (10 March 1604 – 16 March 1670) was a German-Dutch alchemy, alchemist and chemist. Some historians of science have described him as one of the first chemical engineers. His discovery of sodium sulfate in 1625 led to t ...
had recognized that calamine was "nothing else but unmeltable zinc" and that zinc was a "half ripe metal". However some earlier high zinc, low iron brasses such as the 1530 Wightman brass memorial plaque
Plaque may refer to:
Commemorations or awards
* Commemorative plaque, a plate or tablet fixed to a wall to mark an event, person, etc.
* Memorial Plaque (medallion), issued to next-of-kin of dead British military personnel after World War I
* Pl ...
from England may have been made by alloying copper with ''zinc'' and include traces of cadmium
Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, silvery-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Like zinc, it demonstrates oxidation state +2 in most of ...
similar to those found in some zinc ingots from China.
However, the cementation process was not abandoned, and as late as the early 19th century there are descriptions of solid-state
Solid state, or solid matter, is one of the four fundamental states of matter.
Solid state may also refer to:
Electronics
* Solid-state electronics, circuits built of solid materials
* Solid state ionics, study of ionic conductors and their use ...
cementation in a domed furnace at around 900–950 °C and lasting up to 10 hours. The European brass industry continued to flourish into the post medieval period buoyed by innovations such as the 16th century introduction of water powered hammers for the production of wares such as pots.[Day 1990, p. 131] By 1559 the Germany city of Aachen alone was capable of producing 300,000 cwt of brass per year. After several false starts during the 16th and 17th centuries the brass industry was also established in England taking advantage of abundant supplies of cheap copper smelted
Smelting is a process of applying heat to ore, to extract a base metal. It is a form of extractive metallurgy. It is used to extract many metals from their ores, including silver, iron, copper, and other base metals. Smelting uses heat and a c ...
in the new coal
Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen.
Coal is formed when ...
fired reverberatory furnace
A reverberatory furnace is a metallurgical or process furnace that isolates the material being processed from contact with the fuel, but not from contact with combustion gases. The term ''reverberation'' is used here in a generic sense of ''re ...
. In 1723 Bristol
Bristol () is a city, ceremonial county and unitary authority in England. Situated on the River Avon, it is bordered by the ceremonial counties of Gloucestershire to the north and Somerset to the south. Bristol is the most populous city in ...
brass maker Nehemiah Champion patented the use of granulated
Granulation is the process of forming grains or granules from a powdery or solid substance, producing a granular material. It is applied in several technological processes in the chemical and pharmaceutical industries. Typically, granulation invo ...
copper, produced by pouring molten metal into cold water. This increased the surface area of the copper helping it react and zinc contents of up to 33% wt were reported using this new technique.
In 1738 Nehemiah's son William Champion patented a technique for the first industrial scale distillation
Distillation, or classical distillation, is the process of separating the components or substances from a liquid mixture by using selective boiling and condensation, usually inside an apparatus known as a still. Dry distillation is the heat ...
of metallic zinc known as ''distillation per descencum'' or "the English process".[ This local zinc was used in speltering and allowed greater control over the zinc content of brass and the production of high-zinc copper alloys which would have been difficult or impossible to produce using cementation, for use in expensive objects such as ]scientific instruments
A scientific instrument is a device or tool used for scientific purposes, including the study of both natural phenomena and theoretical research.
History
Historically, the definition of a scientific instrument has varied, based on usage, laws, an ...
, clock
A clock or a timepiece is a device used to measure and indicate time. The clock is one of the oldest human inventions, meeting the need to measure intervals of time shorter than the natural units such as the day, the lunar month and t ...
s, brass buttons
A button is a fastener that joins two pieces of fabric together by slipping through a loop or by sliding through a buttonhole.
In modern clothing and fashion design, buttons are commonly made of plastic but also may be made of metal, wood ...
and costume jewelry
Costume or fashion jewelry includes a range of decorative items worn for personal adornment that are manufactured as less expensive ornamentation to complement a particular fashionable outfit or garmentBaker, Lillian. Fifty Years of Collectabl ...
.[Day 1991, p. 183] However Champion continued to use the cheaper calamine cementation method to produce lower-zinc brass and the archaeological remains of bee-hive shaped cementation furnaces have been identified at his works at Warmley
Warmley is a village in South Gloucestershire, England.
Warmley is situated in between Bristol and Bath. It is a parish, with its own church, and has some minor landmarks, such as a World War One memorial the focus of Remembrance Services, and ...
.[ By the mid-to-late 18th century developments in cheaper zinc distillation such as John-Jaques Dony's horizontal furnaces in Belgium and the reduction of tariffs on zinc as well as demand for ]corrosion
Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engi ...
-resistant high zinc alloys increased the popularity of speltering and as a result cementation was largely abandoned by the mid-19th century.[Day 1991, pp. 192–93, Craddock and Eckstein 2003, p. 228]
See also
* Brass bed
*Brass rubbing
Brass rubbing was originally a largely British enthusiasm for reproducing onto paper monumental brasses – commemorative brass plaques found in churches, usually originally on the floor, from between the thirteenth and sixteenth centuries. The ...
*List of copper alloys
Copper alloys are metal alloys that have copper as their principal component. They have high resistance against corrosion. The best known traditional types are bronze, where tin is a significant addition, and brass, using zinc instead. Both of ...
Citations
General references
*Bayley, J. (1990). "The Production of Brass in Antiquity with Particular Reference to Roman Britain". In Craddock, P. T. (ed.). ''2000 Years of Zinc and Brass''. London: British Museum.
*Craddock, P. T. and Eckstein, K (2003). "Production of Brass in Antiquity by Direct Reduction". In Craddock, P. T. and Lang, J. (eds.). ''Mining and Metal Production Through the Ages''. London: British Museum.
*Day, J. (1990). "Brass and Zinc in Europe from the Middle Ages until the 19th century". In Craddock, P. T. (ed.). ''2000 Years of Zinc and Brass''. London: British Museum.
*Day, J. (1991). "Copper, Zinc and Brass Production". In Day, J. and Tylecote, R. F. (eds.). ''The Industrial Revolution in Metals''. London: The Institute of Metals.
*
*Rehren, T. and Martinon Torres, M. (2008) "Naturam ars imitate: European brassmaking between craft and science". In Martinon-Torres, M. and Rehren, T. (eds.). ''Archaeology, History and Science: Integrating Approaches to Ancient Material''. Left Coast Press.
External links
*
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Copper alloys
History of metallurgy
Zinc alloys