Are Brass Knuckles Legal in California? (2026 Penal Code 21810)

Brass knuckles are illegal in California, and the ban reaches far past carrying them. Under California Penal Code section 21810, anyone who makes, imports, sells, offers for sale, gives, lends or simply possesses metal knuckles can be punished by up to one year in county jail as a misdemeanor, or by 16 months, two or three years under Penal Code section 1170(h) as a felony. A second statute, section 21710, makes it a misdemeanor to possess composite or hard wooden knuckles. For how other states treat the same item, see our guide to brass knuckles laws by state.

Information last verified on 2026-10-08. This article has not been reviewed by a licensed lawyer.

Jurisdiction scope: This article covers California state law: the metal knuckles offense in Penal Code 21810 and its definition in 16920, the composite and wooden knuckles offense in 21710 and its definitions in 16405 and 16680, the nuisance provision in 21890 and its enforcement in 18010, the generally prohibited weapon list in 16590 and its exemptions in 17700 through 17745, the place-based offenses in 171b, 171c, 626.10, 4502 and 4574, the felony and misdemeanor rules in Penal Code 17, 18, 19 and 1170(h), and Government Code 53071. It does not cover city or county ordinances, federal property, tribal land, or the law of other states.

What California law says about brass knuckles

California treats metal knuckles as contraband. Penal Code section 21810 reads:

"Except as provided in Chapter 1 (commencing with Section 17700) of Division 2 of Title 2, any person in this state who manufactures or causes to be manufactured, imports into the state, keeps for sale, or offers or exposes for sale, or who gives, lends, or possesses any metal knuckles is punishable by imprisonment in a county jail not exceeding one year or imprisonment pursuant to subdivision (h) of Section 1170." Cal. Penal Code 21810

The list of acts is broad. It covers the whole life of the item: making it, bringing it into California, stocking it, offering it for sale, handing it to someone as a gift or a loan, and having it. The section has no carry element, no place element and no intent element, so it applies to a set kept in a drawer at home as much as to a set in a pocket.

Section 21890 adds that, except as provided in the same exemption chapter, "metal knuckles are a nuisance and are subject to Section 18010." Under Penal Code 18010, metal knuckles are subject to confiscation and summary destruction whenever found in California, and the Attorney General, a district attorney or a city attorney may sue to stop their manufacture, import, sale, giving, lending or possession.

Metal knuckles also appear on California's list of "generally prohibited weapons." Penal Code 16590(o) lists "Metal knuckles, as prohibited by Section 21810." That label matters because the exemption sections and several place-based offenses refer back to the 16590 list rather than to 21810 by name.

What counts as metal knuckles

The definition in Penal Code 16920 applies throughout the part of the Penal Code that governs deadly weapons:

"As used in this part, "metal knuckles" means any device or instrument made wholly or partially of metal that is worn for purposes of offense or defense in or on the hand and that either protects the wearer's hand while striking a blow or increases the force of impact from the blow or injury to the individual receiving the blow. The metal contained in the device may help support the hand or fist, provide a shield to protect it, or consist of projections or studs which would contact the individual receiving a blow." Cal. Penal Code 16920

Two points follow from the text. First, the device need only be "wholly or partially" metal, so an item made mostly of another material can still meet the definition if it contains metal that serves one of the listed functions. Second, the test turns on design and purpose: the device must be worn in or on the hand "for purposes of offense or defense" and must either protect the hand while striking or increase the force of the blow.

Plastic, composite and wooden knuckles

California does not stop at metal. Penal Code 21710 creates a separate offense:

"Any person in this state who possesses, commercially manufactures or causes to be commercially manufactured, or who knowingly imports into the state for commercial sale, keeps for commercial sale, or offers or exposes for commercial sale, any composite knuckles or hard wooden knuckles is guilty of a misdemeanor." Cal. Penal Code 21710

Both terms are defined elsewhere in the same part of the Penal Code. Section 16405 defines composite knuckles as any device or instrument made wholly or partially of composite materials, other than a medically prescribed prosthetic, that is not metal knuckles, is worn in or on the hand for offense or defense, and either protects the wearer's hand while striking a blow or increases the force of the blow. Section 16680 applies the same test to hard wooden knuckles, made wholly or partially of wood or paper products. Neither definition explains what "composite materials" means, so the text does not settle whether every plastic or polymer set qualifies, but a plastic set built to be worn on the hand for striking fits the rest of the 16405 description and carries a real risk of prosecution under 21710. A set that contains metal in one of the ways described in 16920 can fall under the metal knuckles definition instead, whatever its main material.

Note the difference in wording between the two offenses. Section 21810 reaches anyone who "gives, lends, or possesses" metal knuckles. Section 21710 reaches possession and commercial manufacture, import and sale of composite or wooden knuckles; it does not mention giving or lending.

Owning, buying and selling

Owning metal knuckles is itself the offense under 21810. Buying a set results in possession, and every step on the seller's side (keeping for sale, offering or exposing for sale, giving) is named in the statute. Importing knuckles into the state is listed too.

For composite and hard wooden knuckles, 21710 makes possession a misdemeanor and covers commercial manufacture, knowing import for commercial sale, keeping for commercial sale, and offering or exposing for commercial sale.

Carrying concealed, carrying openly, and keeping knuckles in a car

California has no separate rule for carrying knuckles concealed, carrying them openly, or keeping them in a vehicle, because possession anywhere in the state is already an offense under 21810. The Penal Code's knuckles division, sections 21710 through 21890, contains three sections: 21710 on composite and hard wooden knuckles, and 21810 and 21890 on metal knuckles. None of them makes an exception for a home, a business or a car.

Penalties

The penalties depend on which statute applies.

Because 21810 allows either a county jail term of up to one year or imprisonment under Penal Code 1170(h), it can be charged as a misdemeanor or a felony. Penal Code 17(a) treats a crime punishable under 1170(h) as a felony, and 17(b) makes it a misdemeanor in listed situations, such as a sentence other than 1170(h) or a court or prosecutor designating it a misdemeanor. As a felony, the term under 1170(h)(1) is 16 months, two or three years. Section 21710, by contrast, uses the word "misdemeanor" without setting a punishment, so the general rule in Penal Code 19 supplies the range: "imprisonment in the county jail not exceeding six months, or by fine not exceeding one thousand dollars ($1,000), or by both."

Who is exempt

The 21810 offense applies "except as provided in" the exemption chapter that begins at Penal Code 17700. Those exemptions are written for institutions and narrow situations, not for private owners:

• Law enforcement agencies. Section 17730(a) exempts the sale to, possession of, or purchase of a weapon by a federal, state, county, city and county, or city agency charged with enforcing any law, for use in its official duties.
• Peace officers on duty. Section 17730(b) exempts possession by a peace officer of such an agency "when the officer is on duty and the use is authorized by the agency and is within the course and scope of the officer's duties."
• Museums and historical collections. Section 17715 exempts an item possessed by a federal, state or local historical society, museum, or institutional collection that is open to the public, if the item is properly housed and secured from unauthorized handling.
• Film, television and entertainment. Section 17720 exempts an item possessed or used during a motion picture, television or video production or entertainment event by an authorized participant, or by an authorized employee or agent of the entity producing it.
• Found items taken to police. Section 17735 exempts a non-firearm weapon found and possessed by a person who is not prohibited from possessing firearms or ammunition under the statutes it lists, if the person keeps it no longer than necessary to deliver or transport it to a law enforcement agency for disposition according to law.
• Forensic laboratories. Section 17745 exempts possession by a forensic laboratory or its authorized agents or employees in the course and scope of their authorized activities.
• Suppliers to exempt institutions. Sections 17725 and 17730(c) exempt a business that sells these items solely to museums and productions, or solely to law enforcement agencies, when dealing with those entities.

There is no collector or antique exemption for knuckles. The antique exemption in 17700 applies to "any antique firearm," and the curio or relic exemption in 17705 applies to "any firearm or ammunition that is a curio or relic." Neither reaches knuckles. An off-duty peace officer acting privately is also outside 17730(b), which requires that the officer be on duty and acting within the scope of duty.

Knuckle knives and trench-style knives

The knuckles division does not mention knives. Whether a knife with a knuckle guard is also "metal knuckles" depends on the 16920 test: a device made wholly or partially of metal, worn in or on the hand for offense or defense, that protects the hand while striking or increases the force of the blow. The statute does not resolve how that test applies to a combined knife and knuckle guard, and the knife itself is governed by California's separate knife statutes. For those, see our guide to California knife laws.

Public buildings, the State Capitol, schools and jails

State and local public buildings. Penal Code 171b(a) makes it an offense to bring or possess, "within any state or local public building or at any meeting required to be open to the public" under the Government Code's open-meeting laws, "any deadly weapon described in Section 17235 or in any provision listed in Section 16590." Because 16590(o) lists metal knuckles, they are covered. The offense is punishable by up to one year in county jail or by state prison, subject to the exceptions the section lists.

The State Capitol. Penal Code 171c(a) covers the State Capitol, any legislative office, hearing rooms where Senate or Assembly committees are meeting, the Legislative Office Building at 1020 N Street and the state office building at 1021 O Street in Sacramento, and the Capitol grounds. Possessing a deadly weapon described "in any provision listed in Section 16590" there is a misdemeanor punishable by up to one year in county jail, a fine of up to $1,000, or both, "if the area is posted with a statement providing reasonable notice that prosecution may result."

Schools. California's school-grounds weapons statute, Penal Code 626.10(a)(1), lists dirks, daggers, ice picks, knives with blades longer than 2 1/2 inches, locking folding knives, razors with unguarded blades, tasers, stun guns, BB and pellet guns, and spot marker guns. It does not name metal knuckles. Knuckles at a school are still reached by 21810, which makes possession an offense everywhere in the state.

Jails and prisons. Penal Code 4502(a) names metal knuckles directly. Anyone who, while at or confined in a state prison, prison camp or farm, county jail or county road camp, while being taken to or from one, or while in the custody of its officials, possesses or has control of metal knuckles commits a felony punishable under 1170(h) by two, three or four years, served consecutively. Making or attempting to make them there is a felony under 4502(b), punishable by 16 months, two or three years, also served consecutively.

Separately, Penal Code 4574(a) makes it a felony, punishable under 1170(h) by two, three or four years, to knowingly bring or send "any firearms, deadly weapons, or explosives" into a state prison, prison road camp, jail, county road camp, or the grounds belonging or adjacent to them. Section 4574 does not define "deadly weapons" or name knuckles, so its own text does not settle whether knuckles fall within it; possession there remains an offense under 21810 either way.

Minors and brass knuckles

Section 21810 applies to "any person in this state" and sets no age threshold, so a minor who possesses metal knuckles is covered by the same offense. The knuckles division contains no separate section for minors. Because 21810 also reaches anyone who "gives" or "lends" metal knuckles, handing a set to a young person is itself within the statute.

City and county rules

California's firearms preemption statute, Government Code 53071, declares the Legislature's intent "to occupy the whole field of regulation of the registration or licensing of commercially manufactured firearms." It is limited to that firearms field and does not address knuckles. Check your city or county municipal code, or ask the local police department's non-emergency line, for any local rule.

Self-defense alternatives under California law

Readers looking at knuckles for personal protection often compare other tools. California's rules on sprays and stun devices are covered in our guide to California pepper spray and stun gun laws, and the rules on when force may be used at all are in California self-defense laws.

Related pages

• Brass knuckles laws by state
• California knife laws
• California pepper spray and stun gun laws
• California self-defense laws

This article provides general legal information about California state law, not legal advice. Weapons laws change and local rules vary. For advice about a specific situation, contact a lawyer licensed in California or your local law enforcement agency.

Last updated: 2026-10-08.

Frequently Asked Questions

Are brass knuckles legal in California?

No. Penal Code 21810 makes it an offense to make, import, sell, give, lend or possess metal knuckles, which can be charged as a misdemeanor with up to one year in county jail, or as a felony with 16 months, two or three years under Penal Code 1170(h).

Can I keep brass knuckles at home in California?

Section 21810 makes possession itself the offense and has no exception for a home. The exemptions in Penal Code 17700 and following cover agencies, on-duty officers, public museums, film productions, forensic laboratories, businesses that supply only those institutions and found items taken to police, not private owners.

Are plastic knuckles legal in California?

Penal Code 21710 makes it a misdemeanor to possess composite knuckles or hard wooden knuckles, and Penal Code 16405 defines composite knuckles as a device made wholly or partially of composite materials, worn in or on the hand for offense or defense, that protects the hand while striking or increases the force of the blow. The code does not say what counts as composite materials, but a plastic set built for striking fits the rest of that definition. A set that contains metal in the ways described in Penal Code 16920 can count as metal knuckles under 21810.

What is the penalty for brass knuckles in California?

Metal knuckles under Penal Code 21810 carry up to one year in county jail as a misdemeanor, or 16 months, two or three years under Penal Code 1170(h) as a felony. Composite or hard wooden knuckles under 21710 are a misdemeanor, which under Penal Code 19 means up to six months in county jail, a fine of up to $1,000, or both.

Can I buy or sell brass knuckles in California?

No. Section 21810 lists manufacturing, importing, keeping for sale, offering or exposing for sale, and giving or lending metal knuckles, and a buyer who takes a set possesses it.

Can I collect antique brass knuckles in California?

The antique and curio or relic exemptions in Penal Code 17700 and 17705 apply only to firearms. The collection exemption in 17715 is limited to historical societies, museums and institutional collections open to the public, with the item properly housed and secured.

Can I keep brass knuckles in my car in California?

Possession anywhere in the state is an offense under Penal Code 21810, and the statute has no vehicle exception.