TheInfoList

Body armor, also known as body armour, personal armor/armour, or a suit/coat of armour, is protective clothing designed to absorb or deflect physical attacks. Historically used to protect
military personnel Military personnel are members of the state's armed forces A military, also known collectively as armed forces, is a heavily armed, highly organized force primarily intended for warfare. It is typically authorized and maintained by a sovere ...
, today it is also used by various types of
police The police are a constituted body of persons A person (plural people or persons) is a being that has certain capacities or attributes such as reason Reason is the capacity of consciously applying logic by Logical consequence, drawing con ...

(
riot police Riot police are police who are organized, deployed, trained or equipped to confront crowds, protests or riots. Riot police may be regular police who act in the role of riot police in particular situations or they may be separate units organized w ...
in particular), private
security guard#REDIRECT Security guard A security guard (also known as a security inspector, security officer, or protective agent) is a person employed by a government or private party to protect the employing party's assets (property Property (''latin: Res ...
s or
bodyguard A bodyguard (or close protection officer/operative) is a type of , government officer, or who protects a person or a group of people - usually high-ranking public officials or officers, wealthy people, and celebrities — from danger: generall ...
s, and occasionally ordinary civilians. Today there are two main types: regular non-plated body armor for moderate to substantial protection, and hard-plate reinforced body armor for maximum protection, such as used by combat soldiers.

# History

Many factors have affected the development of personal armor throughout human history. Significant factors in the development of armor include the economic and technological necessities of armor production. For instance full
plate armor Plate armour is a historical type of personal body armour made from bronze Bronze is an alloy consisting primarily of copper Copper is a chemical element with the Symbol (chemistry), symbol Cu (from la, cuprum) and atomic number 29. ...
first appeared in Medieval Europe when water-powered
trip hammer The trip hammer of the St. Michael's Furnace property, at the Museum of Iron in Saint-Hubert (Belgium). A trip hammer, also known as a tilt hammer or helve hammer, is a massive powered hammer A hammer is a tool A tool is an objec ...
s made the formation of plates faster and cheaper. At times the development of armor has run parallel to the development of increasingly effective weaponry on the battlefield, with armorers seeking to create better protection without sacrificing mobility.

## Ancient

The first record of body armor in history was found on the
Stele of Vultures The Stele of the Vultures is a monument from the Early Dynastic Period (Mesopotamia), Early Dynastic III period (2600–2350 BC) in Mesopotamia celebrating a victory of the city-state of Lagash over its neighbour Umma. It shows various battle and r ...
in in today's south
Iraq Iraq ( ar, الْعِرَاق, translit=al-ʿIrāq; ku, عێراق, translit=Êraq), officially the Republic of Iraq ( ar, جُمْهُورِيَّة ٱلْعِرَاق '; ku, کۆماری عێراق, translit=Komarî Êraq), is a country i ...

. The oldest known Western armor is the
Dendra panoply Dendra ( el, Δενδρά) is a prehistoric Prehistory, also known as pre-literary history, is the period of human history Human history, also known as world history, is the description of humanity's past. It is informed by archaeology ...
, dating from the Mycenaean Era around 1400 BC.
Mail The mail or post is a system for physically transporting postcard A postcard or post card is a piece of thick paper or thin Card stock, cardboard, typically rectangular, intended for writing and mailing without an envelope. Non-rectangular s ...
, also referred to as chainmail, is made of interlocking iron rings, which may be riveted or welded shut. It is believed to have been invented by
Celt The Celts (, see pronunciation of ''Celt'' for different usages) are. "CELTS location: Greater Europe time period: Second millennium B.C.E. to present ancestry: Celtic a collection of Indo-European peoples. "The Celts, an ancient Indo-Europe ...

ic people in Europe about 500 BC. Most cultures who used mail used the Celtic word or a variant, suggesting the Celts as the originators. The Romans widely adopted mail as the
lorica hamata Image:Lorica Hamata.jpg, Reconstruction of a Roman legionaryThe ''lorica hamata'' (in Latin with normal elision: ) is a type of mail (armour), mail armour used by soldiers for over 600 years (3rd century BC to 4th century AD) from the Roman Republ ...

, although they also made use of
lorica segmentata The ''lorica segmentata'' (), also called ''lorica lamminata'' (; see §Name), is a type of personal armour Body armor, also known as body armour, personal armor/armour, or a suit/coat of armour, is protective clothing designed to absorb or def ...

and
lorica squamata Image:Roman scale armour detail.JPG, Detail of a fragment. Each plate has six holes and the scales are linked in rows. Only the "lower most" holes are visible on most scales, while a few show the pair above and the ring fastener passing through the ...
. While no non-metallic armor is known to have survived, it was likely to have been commonplace due to its lower cost. Eastern armor has a long history, beginning in
Ancient China The earliest known written records of the history of China date from as early as 1250 BC, from the Shang dynasty The Shang dynasty (), also historically known as the Yin dynasty (), was a Chinese dynasty Dynasties in Chinese h ...
. In East Asian history laminated armor such as
lamellar A ''lamella'' (plural ''lamellae'') is a small plate or flake, from the Latin, and may also be used to refer to collections of fine sheets of material held adjacent to one another, in a gill-shaped structure, often with fluid in between though some ...

, and styles similar to the
coat of plates 1250 statue of Saint Maurice in the Magdeburg Cathedral, Germany">Magdeburg_Cathedral.html" ;"title="Saint Maurice in the Magdeburg Cathedral">Saint Maurice in the Magdeburg Cathedral, Germany, wearing a coat of plates above his Hauberk and with a ...
, and
brigandine A brigandine is a form of body armour Body armor, also known as body armour, personal armor/armour, or a suit/coat of armour, is protective clothing designed to absorb or deflect physical attacks. Historically used to protect military perso ...
were commonly used. Later cuirasses and plates were also used. In pre-Qin dynasty times, leather armor was made out of rhinoceros. The use of iron plate armor on the Korean peninsula was developed during the
Gaya Confederacy Gaya (, ) was a Korean confederacy of territorial polities in the Nakdong River The Nakdong River or Nakdonggang () is the longest river A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake ...
of 42 CE - 562 CE. The iron was mined and refined in the area surrounding Gimhae (Gyeongsangnam Provence, South Korea). Using both vertical and triangular plate design, the plate armor sets consisted of 27 or more individual 1-2mm thick curved plates, which were secured together by nail or hinge. The recovered sets include accessories such as iron arm guards, neck guards, leg guards, and horse armor/bits. The use of these armor types disappeared from use on the Korean Peninsula after the fall of the Gaya Confederacy to the Silla Dynasty, during the three kingdoms era
Three Kingdoms of Korea The Three Kingdoms of Korea () refers to the three kingdoms of Goguryeo Goguryeo (; , 37 BC–668 AD), also called Goryeo (; ), was a Korean kingdom located in the northern and central parts of the and the southern and central parts of ...
in 562 CE.

## Middle Ages

In
European history The history of Europe concerns itself with the discovery and collection, the study, organization and presentation and the interpretation of past events and affairs of the people of Europe since the beginning of written records. During the Neolith ...
, well-known armor types include the
mail The mail or post is a system for physically transporting postcard A postcard or post card is a piece of thick paper or thin Card stock, cardboard, typically rectangular, intended for writing and mailing without an envelope. Non-rectangular s ...
hauberk A hauberk or byrnie is a shirt Charvet shirt from the 1930s, Norsk Folkemuseum, Oslo, Norway A shirt is a cloth garment for the upper body (from the neck to the waist). Originally an undergarment worn exclusively by men, it has become, in Ame ...
of the early medieval age, and the full steel plate harness worn by later
Medieval In the history of Europe The history of Europe concerns itself with the discovery and collection, the study, organization and presentation and the interpretation of past events and affairs of the people of Europe since the beginning of ...

and
Renaissance The Renaissance ( , ) , from , with the same meanings. is a period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, entertainment, and media * Period (music), a concept in ...

knight A knight is a person granted an honorary title of knighthood by a head of state (including the pope) or representative for service to the monarch, the christian denomination, church or the country, especially in a military capacity. Knighthoo ...

s, and a few key components (breast and back plates) by heavy cavalry in several European countries until the first year of World War I (1914–15). The
Japanese armour Scholars agree that Japanese armour first appeared in the 4th century, with the discovery of the cuirass A cuirass (; french: cuirasse, la, coriaceus) is a piece of armour that is formed of a single or multiple pieces of metal or other rigid ...

known today as
samurai were the hereditary military nobility and officer caste of History of Japan#Medieval Japan (1185–1573/1600), medieval and Edo period, early-modern Japan from the late 12th century to their abolition in 1876. They were the well-paid retainer ...

armor appeared in the
Heian period The is the last division of classical Japanese history The first human habitation in the Japanese archipelago has been traced to prehistoric times around 30,000 BCE. The Jōmon period The is the time in Japanese prehistory, traditi ...
. (794－1185) These early samurai armors are called the ''
ō-yoroi The is a prominent example of early Japanese armor worn by the samurai were the hereditary military nobility and officer caste Caste is a form of social stratification characterized by endogamy, hereditary transmission of a style of ...
and '' dō-maru''.式正の鎧・大鎧
Costume Museum

### Plate

Gradually, small additional plates or discs of iron were added to the mail to protect vulnerable areas. By the late 13th century, the knees were capped, and two circular discs, called
besagew Armour displaying besagues (:Image:Dresden-Zwinger-Armoury-Armor.13.JPG, full image) Besagews, also spelled besagues, are a type of Rondel (armour), rondel designed to protect the armpits, as part of a harness of plate armour. The armpits are the ...
s were fitted to protect the underarms. A variety of methods for improving the protection provided by mail were used as armorers seemingly experimented. Hardened leather and splinted construction were used for arm and leg pieces. The
coat of plates 1250 statue of Saint Maurice in the Magdeburg Cathedral, Germany">Magdeburg_Cathedral.html" ;"title="Saint Maurice in the Magdeburg Cathedral">Saint Maurice in the Magdeburg Cathedral, Germany, wearing a coat of plates above his Hauberk and with a ...
was developed, an armor made of large plates sewn inside a textile or leather coat. Early plate in Italy, and elsewhere in the 13th to 15th centuries were made of iron. Iron armor could be carburized or
case hardened Case-hardening or surface hardening is the process of hardening the surface of a metal object while allowing the metal deeper underneath to remain soft, thus forming a thin layer of harder metal at the surface. For iron or steel with low carbon ...
to give a surface of harder steel. Plate armor became cheaper than mail by the 15th century as it required much less labor and labor had become much more expensive after the
Black Death The Black Death (also known as the Pestilence, the Great Mortality or the Plague) was a bubonic plague pandemic occurring in Afro-Eurasia from 1346 to 1353. It is the List of epidemics, most fatal pandemic recorded in human history, causing th ...

, though it did require larger furnaces to produce larger blooms. Mail continued to be used to protect those joints which could not be adequately protected by plate, such as the armpit, crook of the elbow and groin. Another advantage of plate was that a lance rest could be fitted to the breast plate. The small skull cap evolved into a bigger true helmet, the
bascinet The bascinet – also bassinet, basinet, or bazineto – was a Medieval In the history of Europe The history of Europe concerns itself with the discovery and collection, the study, organization and presentation and the interpre ...

, as it was lengthened downward to protect the back of the neck and the sides of the head. Additionally, several new forms of fully enclosed helmets were introduced in the late 14th century to replace the
great helm The great helm or heaume, also called pot helm, bucket helm and barrel helm, is a helmet of the High Middle Ages The High Middle Ages, or High Medieval Period, was the period Period may refer to: Common uses * Era, a length or span of time ...
, such as the
sallet The sallet (also called ''celata,'' ''salade'' and ''schaller'') was a combat helmet#REDIRECT Combat helmet A combat helmet or battle helmet is a type of helmet, a piece of personal armor designed specifically to protect the head during comba ...

and
barbute A barbute (also termed a barbuta, which in Italian literally means "bearded", possibly because the beard of a wearer would be visible) is a visorless war helmet of 15th-century Italian design, often with a distinctive "T" shaped or "Y" shaped o ...
and later the
armet The armet is a type of helmet A helmet is a form of protective gear Personal protective equipment (PPE) is protective clothing, helmets, goggles, or other garments or equipment designed to protect the wearer's body from injury or infec ...

and
close helm The close helmet or close helm is a type of military helmet that was worn by knights A knight is a person granted an honorary title A title is one or more words used before or after a person's name, in certain contexts. It may signify eit ...
. Probably the most recognized style of armor in the world became the
plate armor Plate armour is a historical type of personal body armour made from bronze Bronze is an alloy consisting primarily of copper Copper is a chemical element with the Symbol (chemistry), symbol Cu (from la, cuprum) and atomic number 29. ...
associated with the
knight A knight is a person granted an honorary title of knighthood by a head of state (including the pope) or representative for service to the monarch, the christian denomination, church or the country, especially in a military capacity. Knighthoo ...

s of the European
Late Middle Ages The Late Middle Ages or Late Medieval Period was the period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, entertainment, and media * Period (music), a concept in musical com ...
, but continuing to the early 17th-century
Age of Enlightenment The Age of Enlightenment (also known as the Age of Reason or simply the Enlightenment); ger, Aufklärung, "Enlightenment"; it, L'Illuminismo, "Enlightenment"; pl, Oświecenie , "Enlightenment"; pt, Iluminismo, "Enlightenment"; es, link= ...
in all European countries. By about 1400 the full harness of plate armor had been developed in armories of Lombardy Heavy cavalry dominated the battlefield for centuries in part because of their armor. In the early 15th century, small "
hand cannon The hand cannon (Chinese Chinese can refer to: * Something related to China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the List of countries and dependencies by population, world's most popu ...

" first began to be used, in the
Hussite Wars The Hussite Wars, also called the Bohemian Wars or the Hussite Revolution, were a series of wars fought between the and the combined Catholic forces of , the , European monarchs loyal to the , as well as various Hussite factions. After initial ...
, in combination with
Wagenburg A wagon fort, wagon fortress, or corral, often referred to as Circle the wagons (idiom), circling the wagons, is a temporary fortification made of wagons arranged into a rectangle, circle, or other shape and possibly joined with each other to prod ...

tactics, allowing infantry to defeat armored knights on the battlefield. At the same time
crossbow A crossbow is a ranged weapon using an Elasticity (physics), elastic launching device consisting of a bow (archery), bow-like assembly called a ''prod'', mounted horizontally on a main frame called a ''tiller'', which is hand-held in a similar ...

s were made more powerful to pierce armor, and the development of the Swiss
Pike square The pike square (german: Gevierthaufen ("square crowd") or Gewalthaufen, (''crowd of force'')) was a military tactic developed by the Swiss Confederacy The Old Swiss Confederacy or Swiss Confederacy, Swiss Confederation (Modern German New ...
formation also created substantial problems for heavy cavalry. Rather than dooming the use of body armor, the threat of small firearms intensified the use and further refinement of plate armor. There was a 150-year period in which better and more metallurgically advanced steel armor was being used, precisely because of the danger posed by the gun. Hence, guns and cavalry in plate armor were "threat and remedy" together on the battlefield for almost 400 years. By the 15th century Italian armor plates were almost always made of steel. In Southern Germany armorers began to harden their steel armor only in the late 15th century. They would continue to harden their steel for the next century because they
quench In materials science The interdisciplinary Interdisciplinarity or interdisciplinary studies involves the combination of two or more academic discipline An academic discipline or academic field is a subdivision of knowledge that is Edu ...

ed and tempered their product which allowed for the
fire-gilding Gilding is a decorative technique for applying a very thin coating of gold to solid surfaces such as metal (most common), wood, porcelain, or stone. A gilded object is also described as "gilt". Where metal is gilded, the metal below was traditi ...
to be combined with tempering. The quality of the metal used in armor deteriorated as armies became bigger and armor was made thicker, necessitating breeding of larger cavalry horses. If during the 14th and 15th centuries armor seldom weighed more than 15 kg, then by the late 16th century it weighed 25 kg. The increasing weight and thickness of late 16th-century armor therefore gave substantial resistance. In the early years of pistol and
arquebuses An arquebus ( ) is a form of long gun that appeared in Europe and the Ottoman Empire during the 15th century. An infantryman armed with an arquebus is called an arquebusier. Although the term ''arquebus'', derived from the Dutch word ''Haakbus' ...
, firearms were relatively low in velocity. The full suits of armor, or breast plates actually stopped bullets fired from a modest distance. The front breast plates were, in fact, commonly shot as a test. The impact point would often be encircled with engraving to point it out. This was called the "proof". Armor often also bore an insignia of the maker, especially if it was of good quality. Crossbow bolts, if still used, would seldom penetrate good plate, nor would any bullet unless fired from close range. In effect, rather than making plate armor obsolete, the use of firearms stimulated the development of plate armor into its later stages. For most of that period, it allowed horsemen to fight while being the targets of defending arquebusiers without being easily killed. Full suits of armor were actually worn by generals and princely commanders right up to the 1710s.

### Horse armor

The horse was afforded protection from lances and infantry weapons by steel plate
barding Barding (also spelled ''bard'' or ''barb'') is body armour Body armor, also known as body armour, personal armor/armour, or a suit/coat of armour, is protective clothing designed to absorb or deflect physical attacks. Historically used to prot ...
. This gave the horse protection and enhanced the visual impression of a mounted knight. Late in the era, elaborate barding was used in parade armor.

## Gunpowder era

As gunpowder weapons improved, it became cheaper and more effective to have groups of unarmored men with early guns than to have expensive knights, which caused armor to be largely discarded. Cavalry units continued to use armor. Examples include the German
Reiter Image:Reitschwert by Wendelin Boeheim.jpg, left, (Reiter swords), from Wendelin Boeheim, ''Waffenkunde'' (1890), figs. 281–283 ''Reiter'' or ''Schwarze Reiter'' ("black riders", anglicized ''swart reiters'') were a type of cavalry ...

, Polish heavy
hussars A hussar ( , ; hu, huszár, pl, huzar, sr, хусар, husar, hr, husar) was a member of a class of light cavalry Light cavalry comprises lightly armed and armor Armour (British English British English (BrE) is the stan ...
and the back and breast worn by heavy cavalry units during the Napoleonic wars.

## Late modern use

Metal armor remained in limited use long after its general obsolescence. Soldiers in the
American Civil War The American Civil War (also known by other names Other most often refers to: * Other (philosophy), a concept in psychology and philosophy Other or The Other may also refer to: Books * The Other (Tryon novel), ''The Other'' (Tryon nove ...
(1861–1865) bought iron and steel vests from peddlers (both sides had considered but rejected it for standard issue). The effectiveness of the vests varied widely—some successfully deflected bullets and saved lives but others were poorly made and resulted in tragedy for the soldiers. In any case the vests were abandoned by many soldiers due to their weight on long marches as well as the stigma they got for being cowards from their fellow troops.At the start of
World War I World War I, often abbreviated as WWI or WW1, also known as the First World War or the Great War, was a global war A world war is "a war engaged in by all or most of the principal nations of the world". The term is usually reserved for ...

in 1914, thousands of the French
Cuirassier Cuirassiers (; ) were equipped with a , , and s. Cuirassiers first appeared in mid-to-late 16th century Europe as a result of armoured cavalry, such as and s, discarding their s and adopting the use of s as their primary weapon. In the later p ...

s rode out to engage the German Cavalry who likewise used helmets and armor. By that period, the shiny armor plate was covered in dark paint and a canvas wrap covered their elaborate Napoleonic-style helmets. Their armor was meant to protect only against
saber A sabre (French French (french: français(e), link=no) may refer to: * Something of, from, or related to France France (), officially the French Republic (french: link=no, République française), is a country primarily located in Wes ...

s and
lance A lance is a pole weapon A pole weapon or pole arm is a close combat weapon in which the main fighting part of the weapon is fitted to the end of a long shaft, typically of wood, thereby extending the user's effective range and striking pow ...

s. The cavalry had to beware of
rifle A rifle is a long-barrelled firearm A firearm is any type of gun A gun is a ranged weapon designed to use a shooting tube ( gun barrel) to launch typically solid projectiles, but can also project pressurized liquid (e.g. water gu ...

s and
machine gun A machine gun is an auto-firing, rifling, rifled long gun, long-barrel action (firearms)#Autoloading operation, autoloading firearm designed for sustained direct fire with fully powered cartridges. Other automatic firearms such as assault ri ...

s, like the infantry soldiers, who at least had a
trench A trench is a type of or depression in the ground that is generally deeper than it is wide (as opposed to a wider , or ), and narrow compared with its length (as opposed to a simple hole or pit). In , trenches result from by rivers or by geol ...
to give them some protection. By the end of the war the Germans had made some 400,000 ''Sappenpanzer'' suits. Too heavy and restrictive for infantry, most were worn by spotters, sentries, machine gunners and other troops who stayed in one place.

# Modern non-metallic armor

Soldiers use metal or ceramic plates in their bullet resistant vests, providing additional protection from
pistol A pistol is a handgun, more specifically one with the chamber integral to its gun barrel with its massive bore and the stacked barrel A barrel or cask is a hollow cylindrical container with a bulging center, longer than it is wide. Th ...

and
rifle A rifle is a long-barrelled firearm A firearm is any type of gun A gun is a ranged weapon designed to use a shooting tube ( gun barrel) to launch typically solid projectiles, but can also project pressurized liquid (e.g. water gu ...

bullets. Metallic components or tightly-woven fiber layers can give soft armor resistance to stab and slash attacks from
knives A knife (plural knives; from Old Norse Old Norse, Old Nordic, or Old Scandinavian is a stage of development of North Germanic languages, North Germanic dialects before their final divergence into separate Nordic languages. Old Norse wa ...

and
bayonet A bayonet (from French ''baïonnette'') is a knife A knife (plural knives; from Old Norse Old Norse, Old Nordic, or Old Scandinavian is a stage of development of North Germanic languages, North Germanic dialects before their final ...

s.
Chain mail Chain mail (often just mail or sometimes chainmail) is a type of armour consisting of small metal rings linked together in a pattern to form a mesh. It was generally in common military use between the 3rd century BC and the 16th century AD in Eu ...
armored gloves continue to be used by butchers and abattoir workers to prevent cuts and wounds while cutting up carcasses.

## Ceramic

Boron carbide Boron carbide (chemical formula approximately B4C) is an extremely hard boron Boron is a chemical element Image:Simple Periodic Table Chart-blocks.svg, 400px, Periodic table, The periodic table of the chemical elements In chemistry, a ...
is used in hard plate armor capable of defeating rifle and armour piercing ammunition. It was used in armour plates like the SAPI series, and today in most civilian accessible body armours. Other materials include
boron suboxide Boron suboxide (chemical formula B6O) is a solid compound with a structure built of eight icosahedra at the apexes of the rhombohedral unit cell. Each icosahedron is composed of twelve boron atoms. Two oxygen atoms are located in the interstices al ...
,
alumina Aluminium oxide is a of and with the 23. It is the most commonly occurring of several , and specifically identified as aluminium(III) oxide. It is commonly called alumina and may also be called aloxide, aloxite, or alundum depending on part ...

, and
silicon carbide Silicon carbide (SiC), also known as carborundum (), is a semiconductor containing silicon and carbon. It occurs in nature as the extremely rare mineral moissanite. Synthetic SiC powder has been mass-produced since 1893 for use as an abrasive. Gra ...

, which are used for varying reasons from protecting from tungsten carbide penetrators, to improved weight to area ratios. Ceramic body armor is made up of a ceramic strike face and a soft aramid backing to destroy the projectile, before stopping the remains with the backer. It also assists in the removal of energy, by shattering and absorbing the energy in that way without inflicting it against the wearer. This allows such armour to defeat a 5.56/7.62x39mm bullet with little or no felt blunt trauma.

## Fibers

DuPont
Kevlar Kevlar (para-aramid) is a heat-resistant and strong synthetic fiber Synthetic fiber or synthetic fibre (in British English British English (BrE) is the standard dialect A standard language (also standard variety, standard dialect, ...
is well known as a component of some bullet resistant vests and bullet resistant face masks. The PASGT helmet and vest used by
United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

military forces since the early 1980s both have Kevlar as a key component, as do their replacements. Civilian applications include Kevlar reinforced clothing for motorcycle riders to protect against abrasion injuries. Kevlar in non-woven long strand form is used inside an outer protective cover to form chaps that loggers use while operating a chainsaw. If the moving chain contacts and tears through the outer cover, the long fibers of Kevlar tangle, clog, and stop the chain from moving as they get drawn into the workings of the drive mechanism of the saw. Kevlar is used also in emergency services protection gear if it involves high heat, ''e.g.'', tackling a fire, and Kevlar such as vests for police officers, security, and
SWAT In the United States, a SWAT (''special weapons and tactics'') team is generic term for a law enforcement unit that uses specialized or military equipment and tactics. Although they were first created in the 1960s to handle riot control ...

. The latest Kevlar material that DuPont has developed is Kevlar XP. In comparison with "normal" Kevlar, Kevlar XP is more light-weight and more comfortable to wear, as its quilt stitch is not required for the ballistic package. On the other hand,
Twaron Twaron (a brand name of Teijin Aramid Teijin Aramid, formerly known as Teijin Twaron, is a company in The Netherlands that produces various high-strength fibers for industrial purposes, most notably their para-aramid, Twaron. Twaron finds appli ...
is similar to Kevlar. They both belong to the aramid family of synthetic fibers. The only difference is that Twaron was first developed by Akzo in the 1970s. Twaron was first commercially produced in 1986. Now, Twaron is being manufactured by
Teijin Aramid Teijin Aramid, formerly known as Teijin Twaron, is a company in The Netherlands that produces various high-strength fibers for industrial purposes, most notably their para-aramid, Twaron. Twaron finds applications in numerous markets, such as au ...
. Like Kevlar, Twaron is a strong, synthetic fiber. It is also heat resistant and has many applications. It can be used in the production of several materials that include the military, construction, automotive, aerospace, and even sports market sectors. Among the examples of Twaron-made materials are body armor, helmets, ballistic vests, speaker woofers, drumheads, tires, turbo hoses, wire ropes, and cables. Another fiber used to manufacture a bullet-resistant vest is Dyneema
ultra-high-molecular-weight polyethylene Ultra-high-molecular-weight polyethylene (UHMWPE, UHMW) is a subset of the thermoplastic polyethylene Polyethylene or polythene (abbreviated PE; IUPAC name polyethene or poly(methylene)) is the most common plastic in use today. It is a polyme ...
. Originated in the Netherlands, Dyneema has an extremely high strength-to-weight ratio (a 1-mm-diameter rope of Dyneema can bear up to a 240-kg load), is light enough (low density) that it can float on water, and has high energy absorption characteristics. Since the introduction of the Dyneema Force Multiplier Technology in 2013, many body armor manufacturers have switched to Dyneema for their high-end armor solutions.

# Protected areas

## Shield

A
shield A shield is a piece of personal armour held in the hand, which may or may not be strapped to the wrist or forearm. Shields are used to intercept specific attacks, whether from melee weapon, close-ranged weaponry or projectiles such as arrows, ...

is held in the hand or arm. Its purpose is to intercept attacks, either by stopping projectiles such as arrows or by glancing a blow to the side of the shield-user, and it can also be used offensively as a bludgeoning weapon. Shields vary greatly in size, ranging from large shields that protect the user's entire body to small shields that are mostly for use in hand-to-hand combat. Shields also vary a great deal in thickness; whereas some shields were made of thick wooden planking, to protect soldiers from spears and crossbow bolts, other shields were thinner and designed mainly for glancing blows away (such as a sword blow). In prehistory, shields were made of wood, animal hide, or wicker. In antiquity and in the Middle Ages, shields were used by foot soldiers and mounted soldiers. Even after the invention of gunpowder and firearms, shields continued to be used. In the 18th century, Scottish clans continued to use small shields, and in the 19th century, some non-industrialized peoples continued to use shields. In the 20th and 21st centuries, shields are used by military and police units that specialize in anti-terrorist action,
hostage rescue A hostage is a person seized by a criminal abductor in order to compel another party such as a relative, employer Employment is a relationship between two parties, usually based on contract A contract is a legally binding document betwe ...
, and siege-breaching.

A
combat helmet#REDIRECT Combat helmet A combat helmet or battle helmet is a type of helmet, a piece of personal armor designed specifically to protect the head during combat. History Helmets are among the oldest forms of personal protective equipment and ...
is among the oldest forms of
personal protective equipment Personal protective equipment (PPE) is protective clothing A kanga, worn throughout the African Great Lakes region Clothing (also known as clothes, apparel, and attire) are items worn on the body. Typically, clothing is made of fabr ...
, and is known to have been worn in
ancient India According to consensus in modern genetics, anatomically modern humans first arrived on the Indian subcontinent from Africa between 73,000 and 55,000 years ago. Quote: "Y-Chromosome and Mt-DNA data support the colonization of South Asia by mod ...

around 1700 BC and the
Assyrians Assyrian may refer to: * Assyria, a major Mesopotamian kingdom and empire * Assyrian people, an ethnic group indigenous to the Middle East * Assyrian Church (disambiguation) * Assyrian language (disambiguation) * SS Assyrian, SS ''Assyrian'', seve ...
around 900 BC, followed by the
ancient Greeks Ancient Greece ( el, Ἑλλάς, Hellás) was a civilization belonging to a period of History of Greece, Greek history from the Greek Dark Ages of the 12th–9th centuries BC to the end of Classical Antiquity, antiquity ( AD 600). This era was ...
and
Romans Roman or Romans usually refers to: *Rome , established_title = Founded , established_date = 753 BC , founder = King Romulus , image_map = Map of comune of Rome (metropolitan city of Capital Rome, region Lazio, ...
, throughout the
Middle Ages In the history of Europe The history of Europe concerns itself with the discovery and collection, the study, organization and presentation and the interpretation of past events and affairs of the people of Europe since the beginning of ...
, and up to the modern era. Their materials and construction became more advanced as weapons became more and more powerful. Initially constructed from
leather Leather is a strong, flexible and durable material obtained from the tanning Tanning may refer to: *Tanning (leather), treating animal skins to produce leather *Sun tanning, using the sun to darken pale skin **Indoor tanning, the use of arti ...

and
brass Brass is an alloy An alloy is an admixture of metal A metal (from Ancient Greek, Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appea ...

, and then
bronze Bronze is an alloy An alloy is an admixture of metal A metal (from Ancient Greek, Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appear ...

and
iron Iron () is a chemical element In chemistry Chemistry is the study of the properties and behavior of . It is a that covers the that make up matter to the composed of s, s and s: their composition, structure, properties, behav ...

during the
Bronze Bronze is an alloy An alloy is an admixture of metal A metal (from Ancient Greek, Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appear ...
and
Iron Iron () is a chemical element In chemistry Chemistry is the study of the properties and behavior of . It is a that covers the that make up matter to the composed of s, s and s: their composition, structure, properties, behav ...
Ages, they soon came to be made entirely from forged
steel Steel is an alloy An alloy is an admixture of metal A metal (from Ancient Greek, Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appe ...

in many societies after about AD 950. At that time, they were purely military equipment, protecting the head from cutting blows with
sword A sword is an edged, bladed weapon intended for manual cutting or thrusting. Its blade, longer than a knife A knife (plural knives; from Old Norse Old Norse, Old Nordic, or Old Scandinavian is a stage of development of North Ge ...

s, flying
arrow An arrow is a fin-stabilized projectile launched by a bow and arrow, bow. A typical arrow usually consists of a long, stiff, straight ''shaft'' with a weighty (and usually sharp and pointed) ''arrowhead'' attached to the front end, multiple fi ...

s, and low-velocity
musket A musket is a muzzle-loaded A muzzleloader is any firearm into which the bullet, projectile and usually the propellant charge is loaded from the Muzzle (firearms), muzzle of the gun (i.e., from the forward, open end of the gun's barrel). Th ...
ry. Some late medieval helmets, like the great bascinet, rested on the shoulders and prevented the wearer from turning his head, greatly restricting mobility. During the 18th and 19th centuries, helmets were not widely used in warfare; instead, many armies used unarmored hats that offered no protection against blade or bullet. The arrival of World War I, with its trench warfare and wide use of artillery, led to mass adoption of metal helmets once again, this time with a shape that offered mobility, a low profile, and compatibility with gas masks. Today's militaries often use high-quality helmets made of ballistic materials such as
Kevlar Kevlar (para-aramid) is a heat-resistant and strong synthetic fiber Synthetic fiber or synthetic fibre (in British English British English (BrE) is the standard dialect A standard language (also standard variety, standard dialect, ...
and
Twaron Twaron (a brand name of Teijin Aramid Teijin Aramid, formerly known as Teijin Twaron, is a company in The Netherlands that produces various high-strength fibers for industrial purposes, most notably their para-aramid, Twaron. Twaron finds appli ...
, which have excellent bullet and fragmentation stopping power. Some helmets also have good non-ballistic protective qualities, though many do not. The two most popular ballistic helmet models are the PASGT and the MICH. The
Modular Integrated Communications Helmet The Modular Integrated Communications Helmet (MICH) is a U.S. combat helmet A combat helmet or battle helmet is a type of helmet, a piece of personal armor designed specifically to protect the head during combat. History Helmets are amon ...
(MICH) type helmet has a slightly smaller coverage at the sides which allows tactical headsets and other communication equipment. The MICH model has standard pad suspension and four-point chinstrap. The Personal Armor System for Ground Troops (PASGT) helmet has been in use since 1983 and has slowly been replaced by the MICH helmet. A
ballistic face mask A ballistic face mask, also known as facial armor, is a type of personal armor designed to protect the wearer from ballistic threats. Ballistic face masks are usually made of Kevlar or other bullet resistant materials and the inside of the mask may ...
is designed to protect the wearer from ballistic threats. Ballistic face masks are usually made of kevlar or other bullet-resistant materials and the inside of the mask may be padded for shock absorption, depending on the design. Due to weight restrictions, protection levels range only up to NIJ Level IIIA.

## Torso

A
ballistic vest A ballistic vest or bullet-resistant vest, often called a bulletproof vest, is an item of body armor that helps absorb the impact and reduce or stop penetration to the torso from firearm A firearm is any type of gun designed to be readily car ...
helps absorb the impact from
firearm A firearm is any type of gun A gun is a ranged weapon designed to use a shooting tube ( gun barrel) to launch typically solid projectiles, but can also project pressurized liquid (e.g. water guns/ cannons, spray guns for painting ...
-fired
projectile A projectile is a missile propelled by the exertion of a force In physics, a force is an influence that can change the motion (physics), motion of an Physical object, object. A force can cause an object with mass to change its velocity (e ...

s and
shrapnel Shrapnel may refer to: Military * Shrapnel shell, explosive artillery munitions, generally for anti-personnel use * Shrapnel (fragment), a hard loose material Popular culture *Shrapnel (Radical Comics), ''Shrapnel'' (Radical Comics) Charac ...
from explosions, and is worn on the
torso The torso or trunk is an anatomical terminology, anatomical term for the central part, or the core (anatomy), core, of the body (biology), body of many animals (including humans), from which the head, neck, limb (anatomy), limbs, tail and other a ...

. Soft vests are made from many layers of woven or laminated fibers and can be capable of protecting the wearer from small caliber
handgun A handgun is a short-barrelled firearm that can be held and used with one hand. The two most common handgun sub-types in use today are revolvers and semi-automatic pistols, although other handgun-types such as derringers and machine pistols als ...

and
shotgun A shotgun (also known as a scattergun, or historically as a fowling piece) is a long gun, long-barreled firearm designed to shoot a straight-walled cartridge (firearms), cartridge known as a shotshell, which usually discharges numerous small ...

projectiles, and small fragments from explosives such as
hand grenade A grenade is an explosive weapon typically thrown by hand (also called by the retronym hand grenade), but can also refer to a shell (projectile), shell (explosive projectile) shot from the muzzle of a rifle (as a rifle grenade) or a grenade l ...

s. Metal or ceramic plates can be used with a soft vest, providing additional protection from
rifle A rifle is a long-barrelled firearm A firearm is any type of gun A gun is a ranged weapon designed to use a shooting tube ( gun barrel) to launch typically solid projectiles, but can also project pressurized liquid (e.g. water gu ...

rounds, and metallic components or tightly-woven fiber layers can give soft armor resistance to stab and slash attacks from a
knife A knife (plural knives; from Old Norse 'knife, dirk') is a tool or weapon with a cutting edge or blade, often attached to a handle or hilt. One of the earliest tools used by humanity, knives appeared at least Stone Age, 2.5 million years ago ...

or
bayonet A bayonet (from French ''baïonnette'') is a knife A knife (plural knives; from Old Norse Old Norse, Old Nordic, or Old Scandinavian is a stage of development of North Germanic languages, North Germanic dialects before their final ...

. Soft vests are commonly worn by
police The police are a constituted body of persons A person (plural people or persons) is a being that has certain capacities or attributes such as reason Reason is the capacity of consciously applying logic by Logical consequence, drawing con ...

forces, private citizens and private
security guard#REDIRECT Security guard A security guard (also known as a security inspector, security officer, or protective agent) is a person employed by a government or private party to protect the employing party's assets (property Property (''latin: Res ...
s or
bodyguard A bodyguard (or close protection officer/operative) is a type of , government officer, or who protects a person or a group of people - usually high-ranking public officials or officers, wealthy people, and celebrities — from danger: generall ...
s, whereas hard-plate reinforced vests are mainly worn by combat soldiers, police tactical units and hostage rescue teams. A modern equivalent may combine a ballistic vest with other items of protective clothing, such as a
combat helmet#REDIRECT Combat helmet A combat helmet or battle helmet is a type of helmet, a piece of personal armor designed specifically to protect the head during combat. History Helmets are among the oldest forms of personal protective equipment and ...
. Vests intended for police and military use may also include ballistic shoulder and side protection armor components, and explosive ordnance disposal technicians wear heavy armor and helmets with face visors and spine protection.

## Limbs

Medieval armor often offered protection for all of the limbs, including metal boots for the lower legs, gauntlets for the hands and wrists, and greaves for the legs. Today, protection of limbs from bombs is provided by a
bombsuit A bomb suit, Explosive Ordnance Disposal (EOD) suit or a blast suit is a heavy suit of body armor designed to withstand the pressure generated by a bomb and any fragments the bomb may produce. It is usually worn by trained personnel attempting bo ...
. Most modern soldiers sacrifice limb protection for mobility, since armor thick enough to stop bullets would greatly inhibit movement of the arms and legs.

# Performance standards

Due to the various different types of projectiles, it is often inaccurate to refer to a particular product as "
bulletproof Definition Bulletproofing is the process of making something capable of stopping a bullet or similar high velocity projectiles e.g. shrapnel. The term bullet resistance is often preferred because few, if any, practical materials provide comple ...
" because this suggests that it will protect against any and all projectiles. Instead, the term bullet resistant is generally preferred. Standards are regional. Around the world ammunition varies and armor testing must reflect the threats found locally. According to statistics from the US National Law Enforcement Officers Memorial Fund, "a law enforcement officer’s job is extremely dangerous, with one officer being killed every 53 hours in the line of duty [in the United States. Furthermore, this number is on the rise. In 2011, 173 officers were killed, 68 of them due to a gun-related incident." While many standards exist, a few standards are widely used as models. The US National Institute of Justice ballistic and stab documents are examples of broadly-accepted standards. Since the time that NIJ started testing, the lives of more than 3,000 officers were saved. In addition to the NIJ, the United Kingdom's Home Office Scientific Development Branch (HOSDB—formerly the Police Scientific Development Branch (PSDB)) standards are also used by a number of other countries and organizations. These "model" standards are usually adapted by other countries by following the same basic test methodologies, while changing the specific ammunition tested. NIJ Standard-0101.06 has specific performance
standards Standard may refer to: Flags * Colours, standards and guidons * Standard (flag), a type of flag used for personal identification Norm, convention or requirement * Standard (metrology), an object that bears a defined relationship to a unit of ...
for bullet resistant vests used by law enforcement. This rates vests on the following scale against penetration and also blunt trauma protection (deformation): In 2018 or 2019, NIJ is expected to introduce the new NIJ Standard-0101.07. This new standard will completely replace the NIJ Standard-0101.06. The current system of using Roman numerals (II, IIIA, III, and IV) to indicate the level of threat will disappear and be replaced by a naming convention similar to the standard developed by UK Home Office Scientific Development Branch. HG (Hand Gun) is for soft armor and RF (Rifle) is for hard armor. Another important change is that the test-round velocity for conditioned armor will be the same as that for new armor during testing. For example, for NIJ Standard-0101.06 Level IIIA the .44 Magnum round is currently shot at 408 m/s for conditioned armor and at 436 m/s for new armor. For the NIJ Standard-0101.07, the velocity for both conditioned and new armor will be the same. In January 2012, the NIJ introduced BA 9000, body armor quality management system requirements as a quality standard not unlike ISO 9001 (and much of the standards were based on ISO 9001). In addition to the NIJ and HOSDB standards, other important standards include: the Law enforcement in Germany, German Police's Technische Richtlinie (TR) Ballistische Schutzwesten, Draft International Organization for Standardization, ISO prEN ISO 14876, and Underwriters Laboratories (UL Standard 752). Textile armor is tested for both penetration resistance by bullets and for the impact energy transmitted to the wearer. The "backface signature" or transmitted impact energy is measured by shooting armor mounted in front of a backing material, typically oil-based modelling clay. The clay is used at a controlled temperature and verified for impact flow before testing. After the armor is impacted with the test bullet the vest is removed from the clay and the depth of the indentation in the clay is measured. The backface signature allowed by different test standards can be difficult to compare. Both the clay materials and the bullets used for the test are not common. In general the British, German and other European standards allow 20–25 mm of backface signature, while the US-NIJ standards allow for 44 mm, which can potentially cause internal injury. The allowable backface signature for this has been controversial from its introduction in the first NIJ test standard and the debate as to the relative importance of penetration-resistance vs. backface signature continues in the medical and testing communities. In general a vest's textile material temporarily degrades when wet. Neutral water at room temp does not affect para-aramid or Ultra high molecular weight polyethylene, UHMWPE but acidic, basic and some other solutions can permanently reduce para-aramid fiber tensile strength. (As a result of this, the major test standards call for wet testing of textile armor.) Mechanisms for this wet loss of performance are not known. Vests that will be tested after ISO-type water immersion tend to have heat-sealed enclosures and those that are tested under NIJ-type water spray methods tend to have water-resistant enclosures. From 2003 to 2005, a large study of the environmental degradation of Zylon armor was undertaken by the US-NIJ. This concluded that water, long-term use, and temperature exposure significantly affect tensile strength and the ballistic performance of PBO or Zylon fiber. This NIJ study on vests returned from the field demonstrated that environmental effects on Zylon resulted in ballistic failures under standard test conditions.

## Ballistic testing V50 and V0

Measuring the ballistic performance of armor is based on determining the kinetic energy of a bullet at impact. Because the energy of a bullet is a key factor in its penetrating capacity, velocity is used as the primary independent variable in ballistic testing. For most users the key measurement is the velocity at which no bullets will penetrate the armor. Measuring this zero penetration velocity (V0) must take into account variability in armor performance and test variability. Ballistic testing has a number of sources of variability: the armor, test backing materials, bullet, casing, powder, primer and the gun barrel, to name a few. Variability reduces the predictive power of a determination of V0. If for example, the V0 of an armor design is measured to be with a 9 mm FMJ bullet based on 30 shots, the test is only an estimate of the real V0 of this armor. The problem is variability. If the V0 is tested again with a second group of 30 shots on the same vest design, the result will not be identical. Only a single low velocity penetrating shot is required to reduce the V0 value. The more shots made the lower the V0 will go. In terms of statistics, the zero penetration velocity is the tail end of the distribution curve. If the variability is known and the standard deviation can be calculated, one can rigorously set the V0 at a confidence interval. Test Standards now define how many shots must be used to estimate a V0 for the armor certification. This procedure defines a confidence interval of an estimate of V0. (See "NIJ and HOSDB test methods".) V0 is difficult to measure, so a second concept has been developed in ballistic testing called V50. This is the velocity at which 50 percent of the shots go through and 50 percent are stopped by the armor. US military standards define a commonly used procedure for this test. The goal is to get three shots that penetrate and a second group of three shots that are stopped by the armor all within a specified velocity range. It is possible, and desirable to have a penetration velocity lower than a stop velocity. These three stops and three penetrations can then be used to calculate a V50 velocity. In practice this measurement of V50 often requires 1–2 vest panels and 10–20 shots. A very useful concept in armor testing is the offset velocity between the V0 and V50. If this offset has been measured for an armor design, then V50 data can be used to measure and estimate changes in V0. For vest manufacturing, field evaluation and life testing both V0 and V50 are used. However, as a result of the simplicity of making V50 measurements, this method is more important for control of armor after certification.

### Cunniff analysis

Using dimensionless analysis, Cuniff arrived at a relation connecting the V50 and the system parameters for textile-based body armors. Under the assumption that the energy of impact is dissipated in breaking the yarn, it was shown that :$V_ = \left(U^* \right)^ f\left\left(\frac\right\right).$ Here, :$U^* = \frac\sqrt\frac$ :$\sigma,\epsilon,\rho,E$ are the failure stress, failure strain, density and elastic modulus of the yarn :$A_d$ is the mass per unit area of the armor :$A_p$ is the mass per unit area of the projectile

## Military testing

* Bulletproof vest * International Medieval Combat Federation * Liquid Armor * Osprey body armour

*