Brass knuckles

Brass knuckles, also sometimes called knuckles, knucks, brass knucks, knucklebusters, or knuckledusters, are weapons used in hand-to-hand combat. Brass knuckles are pieces of metal shaped to fit around the knuckles. Despite their name, they are usually made of steel. Designed to preserve and concentrate a punch's force by directing it toward a harder and smaller contact area, they result in increased tissue disruption, including an increased likelihood of fracturing the victim's bones on impact. The extended and rounded palm grip also spreads across the attacker's palm the counter-force that would otherwise be absorbed primarily by the attacker's fingers, reducing the likelihood of damage to the attacker's fingers.

History and variations
Metal ring and knuckle style weapons date back to ancient times and have been used all over the world for many hundreds of years. The Nihang Singhs used a early varient called Sher Panja in the 18 century. Cast iron, brass, lead, and wood knuckles were made in the United States during the American Civil War (1861–1865). Soldiers would often buy cast iron or brass knuckles. If they could not buy them, they would carve their own from wood, or cast them at camp by melting lead bullets and using a mold in the dirt.

Some brass knuckles have rounded rings, which increase the impact of blows. Other instruments (not generally considered to be "brass knuckles" or "metal knuckles" per se) may have spikes, sharp points and cutting edges. These devices come in many variations and are called by a variety of names, including "knuckle knives."

By the late 19th century, knuckledusters were incorporated into various kinds of pistols like the Apache revolvers used by criminals in France in the late 19th century to early 20th century. During World War I the US Army issued two different knuckle knives, the US model 1917 and US model 1918 Mark I trench knives. Knuckles and knuckle knives were also being made in England at the time and purchased privately by British soldiers. By World War II, knuckles and knuckle knives were quite popular with both American and British soldiers. The Model 1918 trench knives were reissued to American paratroopers. British Commandos even had their very own "Death's Head" knuckle knife, featuring a skull-shaped brass knuckle handle.

A notable knuckle knife still in use is the Cuchillo de Paracaidista, issued to Argentinian paratroopers. Current-issue models have an emergency blade in the crossguard.

Legality and distribution
In Canada, brass knuckles, also referred to as "brass monkeys", or any similar devices, are listed as prohibited weapons; possession of such weapon is a criminal offence under the Criminal Code of Canada. Similar legislation has been instituted in Russia and Australia.

In France, brass knuckles are legal, and freely sold to people of legal age (over 18 years old), but carrying them is forbidden. The French term is "poing américain", which literally means "American fist".

In Sweden, brass knuckles are legal to purchase and own, but are not legal to sell or carry in public. The carrying of brass knuckles carry the same penalty as carrying a knife, and falls under the same law. They are called "knogjärn", literally "knuckle iron".

In Brazil, brass knuckles are legal and freely sold. They are called "Soco Inglês," which means "English Punch."

Brass knuckles are illegal in the United Kingdom, Norway, Portugal, Spain, Austria, Croatia, Germany, Belgium, Bosnia and the Netherlands, carrying significant jail sentences and fines for possession of a dangerous weapon.

In the United States, brass knuckles are not significantly regulated at the federal level, but various state, county and city laws prohibit their purchase and/or possession. Some state laws require purchasers to be 18 or older. Most states have statutes regulating the carrying of weapons, and many specifically prohibit brass knuckles or "metal knuckles." Where they are legal, brass knuckles can normally be purchased online or at flea markets, swap meets, and at some sword and weapon shops. Some companies manufacture belt buckles or novelty paper weights that function as brass knuckles and are sold "for entertainment purposes only," a dubious legal standing. Brass knuckles made of hardened plastic, rather than metal, have been marketed as "undetectable by airport metal detectors." A number of states that ban brass knuckles also ban plastic knuckles. New York's criminal law statutes list both "metal knuckles" and "plastic knuckles" as prohibited weapons, but provide no definition for either. Texas does not differentiate with regards to composition materials, making the possession of "knuckles" a Class A misdemeanor. Specifically, Texas makes it an offense to intentionally or knowingly possess, manufacture, transport, repair, or sell prohibited weapons (including knuckles).