File (tool)
   HOME

TheInfoList



OR:

A file is a
tool A tool is an Physical object, object that can extend an individual's ability to modify features of the surrounding environment or help them accomplish a particular task. Although many Tool use by animals, animals use simple tools, only human bei ...
used to remove fine amounts of material from a workpiece. It is common in woodworking,
metalworking Metalworking is the process of shaping and reshaping metals in order to create useful objects, parts, assemblies, and large scale structures. As a term, it covers a wide and diverse range of processes, skills, and tools for producing objects on e ...
, and other similar trade and hobby tasks. Most are hand tools, made of a case hardened
steel Steel is an alloy of iron and carbon that demonstrates improved mechanical properties compared to the pure form of iron. Due to steel's high Young's modulus, elastic modulus, Yield (engineering), yield strength, Fracture, fracture strength a ...
bar of rectangular, square, triangular, or round cross-section, with one or more surfaces cut with sharp, generally parallel teeth. A narrow, pointed tang is common at one end, to which a
handle A handle is a part of, or an attachment to, an object that allows it to be grasped and object manipulation, manipulated by hand. The design of each type of handle involves substantial ergonomics, ergonomic issues, even where these are dealt wi ...
may be fitted.. A rasp is a form of file with distinct, individually cut teeth used for coarsely removing large amounts of material. Files have also been developed with abrasive surfaces, such as natural or synthetic diamond grains or
silicon carbide Silicon carbide (SiC), also known as carborundum (), is a hard chemical compound containing silicon and carbon. A wide bandgap semiconductor, it occurs in nature as the extremely rare mineral moissanite, but has been mass-produced as a powder a ...
, allowing removal of material that would dull or resist steel files, such as
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, porcela ...
.


History

Early filing or rasping has prehistoric roots and grew naturally out of the blending of the twin inspirations of cutting with stone cutting tools (such as
hand axe A hand axe (or handaxe or Acheulean hand axe) is a Prehistory, prehistoric stone tool with two faces that is the longest-used tool in human history. It is made from stone, usually flint or chert that has been "reduced" and shaped from a larger ...
s) and abrading using natural abrasives, such as well-suited types of stone (for example,
sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...
).
pp. 5–15
Relatedly, lapping is also quite ancient, with
wood Wood is a structural tissue/material found as xylem in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulosic fibers that are strong in tension and embedded in a matrix of lignin t ...
and beach
sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is usually defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural ...
offering a natural pair of lap and lapping compound. The Disston authors state, "To abrade, or file, ancient man used sand, grit, coral, bone, fish skin, and gritty woods,—also stone of varying hardness in connection with sand and water." The
Bronze Age The Bronze Age () was a historical period characterised principally by the use of bronze tools and the development of complex urban societies, as well as the adoption of writing in some areas. The Bronze Age is the middle principal period of ...
and the
Iron Age The Iron Age () is the final epoch of the three historical Metal Ages, after the Chalcolithic and Bronze Age. It has also been considered as the final age of the three-age division starting with prehistory (before recorded history) and progre ...
had various kinds of files and rasps. Archaeologists have discovered rasps made from bronze in Egypt, dating back to the years 1200–1000 BC. Archaeologists have also discovered rasps made of iron used by the Assyrians, dating back to the 7th Century BC. During the
Middle Ages In the history of Europe, the Middle Ages or medieval period lasted approximately from the 5th to the late 15th centuries, similarly to the post-classical period of global history. It began with the fall of the Western Roman Empire and ...
files were already quite advanced, thanks to the extensive talents of
blacksmith A blacksmith is a metalsmith who creates objects primarily from wrought iron or steel, but sometimes from #Other metals, other metals, by forging the metal, using tools to hammer, bend, and cut (cf. tinsmith). Blacksmiths produce objects such ...
s.
pp. 16–17
By the 11th century, there already existed hardened files that would seem quite modern even to today's eyes. But although they existed, and could even have spread widely, in a geographical sense, via
trade Trade involves the transfer of goods and services from one person or entity to another, often in exchange for money. Economists refer to a system or network that allows trade as a market. Traders generally negotiate through a medium of cr ...
, they were not widespread in the cultural sense of the word—that is, most people, and even many smiths, did not have them. For example, in the 13th century, ornamental iron work at
Paris Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...
was done skillfully with the aid of files, but the process was a secret known only to a master craftsman. The Disston authors state, "It was not until the fourteenth century, however, that those who practiced art in ironwork began to use other tools, besides heat and the hammer, regularly." This statement could mislead in the sense that stoning (with sandstone) and lapping (with wood, sand, and water) have never been rare activities among humans, or especially smiths. But the point is that modern iron or steel files, with teeth and hardening, and the
material culture Material culture is culture manifested by the Artifact (archaeology), physical objects and architecture of a society. The term is primarily used in archaeology and anthropology, but is also of interest to sociology, geography and history. The fie ...
of intricate filing that would lead to
locksmithing Locksmithing is the work of creating and bypassing locks. Locksmithing is a traditional trade and in many countries requires completion of an apprenticeship. The level of formal education legally required varies by country, ranging from no formal ...
and
gunsmith A gunsmith is a person who repairs, modifies, designs, or builds guns. The occupation differs from an armorer, who usually replaces only worn parts in standard firearms. Gunsmiths do modifications and changes to a firearm that may require a very ...
ing, for example, are what took time to become common. But by the
late Middle Ages The late Middle Ages or late medieval period was the Periodization, period of History of Europe, European history lasting from 1300 to 1500 AD. The late Middle Ages followed the High Middle Ages and preceded the onset of the early modern period ( ...
, the transition was extensive. The Disston authors mention
Nuremberg Nuremberg (, ; ; in the local East Franconian dialect: ''Nämberch'' ) is the Franconia#Towns and cities, largest city in Franconia, the List of cities in Bavaria by population, second-largest city in the States of Germany, German state of Bav ...
,
Sheffield Sheffield is a city in South Yorkshire, England, situated south of Leeds and east of Manchester. The city is the administrative centre of the City of Sheffield. It is historically part of the West Riding of Yorkshire and some of its so ...
, and Remscheid (they use the ''Reimscheid'' spelling) as leading centers of production for files as well as tools in general. The activity in Remscheid reflects the metalworking spirit of the
Rhine-Ruhr The Rhine-Ruhr metropolitan region () is the Metropolitan regions in Germany, largest metropolitan region in Germany, with over ten million inhabitants. A wikt:polycentric, polycentric conurbation with several major urban concentrations, the reg ...
region in general (including
Essen Essen () is the central and, after Dortmund, second-largest city of the Ruhr, the largest urban area in Germany. Its population of makes it the fourth-largest city of North Rhine-Westphalia after Cologne, Düsseldorf and Dortmund, as well as ...
,
Düsseldorf Düsseldorf is the capital city of North Rhine-Westphalia, the most populous state of Germany. It is the second-largest city in the state after Cologne and the List of cities in Germany with more than 100,000 inhabitants, seventh-largest city ...
, and
Cologne Cologne ( ; ; ) is the largest city of the States of Germany, German state of North Rhine-Westphalia and the List of cities in Germany by population, fourth-most populous city of Germany with nearly 1.1 million inhabitants in the city pr ...
) rather than representing a single village of geniuses in isolation. (Considering the Disston authors' mention of the blacksmith guilds of 13th-century
Florence Florence ( ; ) is the capital city of the Italy, Italian region of Tuscany. It is also the most populated city in Tuscany, with 362,353 inhabitants, and 989,460 in Metropolitan City of Florence, its metropolitan province as of 2025. Florence ...
and 15th-century England, coupled with their mention of
Nuremberg Nuremberg (, ; ; in the local East Franconian dialect: ''Nämberch'' ) is the Franconia#Towns and cities, largest city in Franconia, the List of cities in Bavaria by population, second-largest city in the States of Germany, German state of Bav ...
,
Sheffield Sheffield is a city in South Yorkshire, England, situated south of Leeds and east of Manchester. The city is the administrative centre of the City of Sheffield. It is historically part of the West Riding of Yorkshire and some of its so ...
, and Remscheid, the region that sweeps from Florence through Nuremberg, the Rhine-Ruhr, the Netherlands, and up to Sheffield, can be compared to the modern economics notation of the Blue Banana.) Most files of the period were smithed by hand in a sequence in which the iron was forged (heated and hammered), then the teeth were cut with a
chisel A chisel is a hand tool with a characteristic Wedge, wedge-shaped cutting edge on the end of its blade. A chisel is useful for carving or cutting a hard material such as woodworking, wood, lapidary, stone, or metalworking, metal. Using a chi ...
(some of this action was just as much upsetting/
swaging Swaging () is a forging process in which the dimensions of an item are altered using Die (manufacturing), dies into which the item is forced. Swaging is usually a cold working process, but also may be hot working, hot worked. The term swage ma ...
as it was cutting), and then the piece was hardened (by heating and then
quenching In materials science, quenching is the rapid cooling of a workpiece in water, gas, oil, polymer, air, or other fluids to obtain certain material properties. A type of heat treating, quenching prevents undesired low-temperature processes, suc ...
), followed sometimes by tempering. Among the drawings of
Leonardo da Vinci Leonardo di ser Piero da Vinci (15 April 1452 - 2 May 1519) was an Italian polymath of the High Renaissance who was active as a painter, draughtsman, engineer, scientist, theorist, sculptor, and architect. While his fame initially rested o ...
is a sketch of a
machine tool A machine tool is a machine for handling or machining metal or other rigid materials, usually by cutting, Boring (manufacturing), boring, grinding (abrasive cutting), grinding, shearing, or other forms of deformations. Machine tools employ some s ...
for the cutting of files (the chisel would make one strike,
swaging Swaging () is a forging process in which the dimensions of an item are altered using Die (manufacturing), dies into which the item is forced. Swaging is usually a cold working process, but also may be hot working, hot worked. The term swage ma ...
a tooth, then automatically advance into position for the next tooth, and strike again). Prior to the industrialization of
machining Machining is a manufacturing process where a desired shape or part is created using the controlled removal of material, most often metal, from a larger piece of raw material by cutting. Machining is a form of subtractive manufacturing, which util ...
and the development of
interchangeable parts Interchangeable parts are parts (wikt:component#Noun, components) that are identical for practical purposes. They are made to specifications that ensure that they are so nearly identical that they will fit into any assembly of the same type. One ...
during the 19th century, filing was much more important in the construction of mechanisms. Component parts were roughly shaped by
forging Forging is a manufacturing process involving the shaping of metal using localized compression (physics), compressive forces. The blows are delivered with a hammer (often a power hammer) or a die (manufacturing), die. Forging is often classif ...
,
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 or ...
, and by primitive
machining Machining is a manufacturing process where a desired shape or part is created using the controlled removal of material, most often metal, from a larger piece of raw material by cutting. Machining is a form of subtractive manufacturing, which util ...
operations. These components were then individually hand-fitted for assembly by careful and deliberate filing. The potential precision of such fitting is much higher than generally assumed, but the components of such hand-fit assemblies are decidedly not interchangeable with those from another assembly.
Lock Lock(s) or Locked 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 entertainme ...
s,
clock A clock or chronometer is a device that measures and displays time. The clock is one of the oldest Invention, human inventions, meeting the need to measure intervals of time shorter than the natural units such as the day, the lunar month, a ...
s, and
firearm A firearm is any type of gun that uses an explosive charge and is designed to be readily carried and operated by an individual. The term is legally defined further in different countries (see legal definitions). The first firearms originate ...
s (flintlocks and earlier) were manufactured in this way for centuries before the
Industrial Revolution The Industrial Revolution, sometimes divided into the First Industrial Revolution and Second Industrial Revolution, was a transitional period of the global economy toward more widespread, efficient and stable manufacturing processes, succee ...
.
Machining Machining is a manufacturing process where a desired shape or part is created using the controlled removal of material, most often metal, from a larger piece of raw material by cutting. Machining is a form of subtractive manufacturing, which util ...
in the mid-19th century was heavily dependent on filing, because
milling Milling may refer to: * Milling (minting), forming narrow ridges around the edge of a coin * Milling (grinding), breaking solid materials into smaller pieces by grinding, crushing, or cutting in a mill * Milling (machining), a process of using ro ...
practice was slowly evolving out of its infancy. As late as the early 20th century,
manufacturing Manufacturing is the creation or production of goods with the help of equipment, labor, machines, tools, and chemical or biological processing or formulation. It is the essence of the secondary sector of the economy. The term may refer ...
often involved filing parts to precise shape and size. In today's manufacturing environment, milling and grinding have generally replaced this type of work, and filing (when it occurs at all) usually tends to be for deburring only. Skillful filing to shape and size is still a part of diemaking, moldmaking, toolmaking, etc., but even in those fields, the goal is usually to avoid handwork when possible.


Types

Files come in a wide variety of materials, sizes, shapes, cuts, and tooth configurations. The cross-section of a file can be flat, round, half-round, triangular, square, knife edge or of a more specialized shape. Steel files are made from high carbon steel (1.0 to 1.25% carbon) and may be through hardened or case hardened. There is no unitary international standard for file nomenclature; however, there are many generally accepted names for certain kinds of files. A file is "blunt" if its sides and width are both parallel throughout its length. It is "tapered" if there is a reduction in its dimensions from its heel toward its point. A file may taper in width, in thickness, or both. A " tang" is a protrusion at the heel, tapered, parallel sided, or conical, for gripping, inserting in a handle, or mounting in a chuck. The ''cut'' of the file refers to how fine its teeth are. They are defined as (from roughest to smoothest): rough, middle, bastard, second cut, smooth, and dead smooth. A ''single-cut'' file has one set of parallel teeth while a ''cross-cut'' or ''double-cut'' file has a second set of cuts forming diamond shaped cutting surfaces. In Swiss-pattern files the teeth are cut at a shallower angle, and are graded by number, with a number 1 file being coarser than a number 2, etc. Most files have teeth on all faces, but some specialty flat files have teeth on only one face or one edge, so that the user can come right up to another edge without damaging the finish on it. Some of the common shapes and their uses: * Barrette files are tapered in width and thickness, coming to a rounded point at the end. Only the flat side is cut, and the other sides are all safe. For doing flat work. * Checkering files parallel in width and gently tapered in thickness. They have teeth cut in a precise grid pattern, and are used for making serrations and doing checkering work, as on gunstocks. * Crochet files are tapered in width and gradually tapered in thickness, with two flats and radiused edges, cut all around. Used in filing junctions between flat and curved surface, and slots with rounded edges. * Crossing files are half round on two sides with one side having a larger radius than the other. Tapered in width and thickness. For filing interior curved surfaces. The double radius makes possible filing at the junction of two curved surfaces or a straight and curved surface. * Dreadnought (curved teeth) and millenicut (straight teeth) files both have heavily undercut, sharp but coarse teeth. Both can be used for rapidly removing large quantities of material from thick aluminum alloy, copper or brass. Today, the millenicut and dreadnought have found a new use in removing plastic filler materials such as two-part epoxies or styrenes such as those commonly used in automobile body repairs. * Equalling files are parallel in width and thickness. Used for filing slots and corners. * Farrier Rasp files are tanged rasps used mainly by farriers and blacksmiths. They are flat with a rasp on one side and double cut on the reverse. * Fret files are square or rectangular with three flat sides and one side having a concave groove. They are used by luthiers to file a rounded "crown" on the frets of guitars and other fretted instruments. The flat faces are used to dress the ends of the frets, removing the sharp edges left after the frets are trimmed to length. *Half round ring files taper in width and thickness, coming to a point, and are narrower than a standard half round. Used for filing inside of rings. *Joint round edge files are parallel in width and thickness, with rounded edges. The flats are safe (no teeth) and cut on the rounded edges only. Used for making joints and hinges. * Knife files are tapered in width and thickness, but the knife edge has the same thickness the whole length, with the knife edge having an arc to it. Used for slotting or wedging operations. * Nut files are fine, precise files in sets of graduated thickness, used by
luthier A luthier ( ; ) is a craftsperson who builds or repairs string instruments. Etymology The word ' is originally French and comes from ''luth'', the French word for "lute". The term was originally used for makers of lutes, but it came to be ...
s for dressing the slots at the end of the neck which support the strings of guitars, violins etc., in the correct position. * Pillar files are parallel in width and tapered in thickness for perfectly flat filing. Double cut top and bottom with both sides safe, these are long, narrow files for precision work. * Pippin files are tapered in width and thickness, generally of a teardrop cross section and having the edge of a knife file. Used for filing the junction of two curved surfaces and making V-shaped slots. *Planemaker's float Floats are straight, single-cut files which taper used for cutting, flattening and smoothing wood, particularly in making wooden hand planes. * Round parallel files are similar to round files, except that they do not taper. Shaped like a toothed cylinder. * Saw sharpening files are usually single cut to deliver a smooth finish. They are suited to sharpening saw blades and dressing tool edges, especially where a finer, sharper edge or smoother surface finish is desired. The Chainsaw file is one example, used primarily for sharpening chainsaws. These appear to have a round cross-section, but are actually shaped to fit snugly against the cutting edge of a chainsaw's teeth. * Slitting files are parallel in width with a diamond-shaped cross section. Thinner than knife files and use for filing slots. * Warding files are parallel in thickness, tapered in width, and thin. Like a hand or flat file that comes to a point on the end. Used for flat work and slotting.


Diamond files

Instead of having teeth cut into the file's working surface, diamond files have small particles of industrial diamond embedded in their surface (or into a softer material that is bonded to the underlying surface of the file). The use of diamonds in this manner allows the file to be used effectively against extremely hard materials, such as stone, glass or very hard metals such as hardened steel or carbide against which a standard steel file is ineffective. Diamond files are also the only type that may be used with a back-and-forth motion without damaging the file. These may also be called diamond laps, as the "teeth" are not regular projections, as in a file, but particles, usually shaped and located randomly and held in place by a softer (any other) material.


Needle files

The image to the left shows a selection of needle files in an assortment of cross sectional shapes. Needle files are small files that are used in applications where the surface finish takes priority over metal removal rates but they are most suited for smaller work pieces. They are often sold in sets, including different shapes.


Riffler files

Riffler files are small to medium-sized files in an assortment of cross sectional shapes and profiles. The varying profiles and shapes enable them to be used in hard to reach, or unusually shaped areas. They are often used as an intermediate step in die making where the surface finish of a cavity die may need to be improved, e.g. in plastic injection moulding or die casting.


Machine files

Files are produced specifically for use in a ''filing machine'', which is similar in appearance to a scroll saw with a vertically reciprocating file mounted in the middle of a table. A workpiece is manipulated around the file's face as the shape requires. A cone point (as pictured in the top and bottom files at left) allows a file to center itself in its mount. Files with flat mounting surfaces must be secured with set screws. Filing machines are rarely seen in modern production environments, but may be found in older toolrooms or diemaking shops as an aid in the manufacture of specialist tooling.


Escapement files

Escapement files, also known as watchmaker's files, are a classification of short, (very) thin files with bastard-cut (medium coarseness) or embedded diamond surfaces, similar to needle files in form and function but smaller. Typical dimensions are on the order of approximately 100–140 mm (4–5 in.) in length and 3–5 mm (– in.) in width. Best used for fine, delicate work on small pieces or mechanisms (such as
escapement An escapement is a mechanical linkage in mechanical watches and clocks that gives impulses to the timekeeping element and periodically releases the gear train to move forward, advancing the clock's hands. The impulse action transfers energy to t ...
s), escapement files are commonly used by clock and watchmakers, as well as in crafting jewelry.


Dental files

During root canal therapy, round files ranging from diameter files are used to smooth the narrow canals of the interior of the tooth and thus facilitate disinfection of the internal surface. Typically the files are made of
stainless steel Stainless steel, also known as inox, corrosion-resistant steel (CRES), or rustless steel, is an iron-based alloy that contains chromium, making it resistant to rust and corrosion. Stainless steel's resistance to corrosion comes from its chromi ...
or
nickel titanium Nickel titanium, also known as nitinol, is a metal alloy of nickel and titanium, where the two elements are present in roughly equal atomic percentages. Different alloys are named according to the weight percentage of nickel; e.g., nitinol 55 and ...
(NiTi) and come in a variety of styles. Mechanized files, known as rotary files, are also commonly used. These files attach to the head of a specific oscillating or rotating drill.


Use

Files have forward-facing cutting teeth, and cut most effectively when pushed over the workpiece. A variety of strokes are employed to stabilize the cutting action and produce a varied result. ''Draw filing'' is an operation in which the file is grasped at each end, and with an even pressure alternately pulled and pushed perpendicularly over the work. A variation involves laying the file sideways on the work, and carefully pushing or pulling it across the work. This catches the teeth of the file sideways instead of head on, and an extremely fine shaving action is produced. There are also varying strokes that produce a combination of the straight ahead stroke and the drawfiling stroke, and very fine work can be attained in this fashion. Using a combination of strokes, and progressively finer files, a skilled operator can attain a surface that is perfectly flat and near flawless finish. ''Pinning'' refers to the clogging of the file teeth with ''pins'', which are material shavings. These pins cause the file to lose its cutting ability and can scratch the workpiece. A ''file card'', which is a brush with metal bristles, is used to clean the file. (The name, "card", is the same as used for the " raising cards" (spiked brushes) used in woolmaking.)
Chalk Chalk is a soft, white, porous, sedimentary carbonate rock. It is a form of limestone composed of the mineral calcite and originally formed deep under the sea by the compression of microscopic plankton that had settled to the sea floor. Ch ...
can help prevent pinning..


See also

* Hand scraper * Rasp


References


Bibliography

* * * *


External links

* {{Authority control