Explainer

Search for knife laws and you will find dozens of state-by-state charts, most published by knife retailers, many contradicting each other. The confusion is not because the law is secret. It is because people look for a federal rule that does not exist in the form they expect.

Here is what federal law actually covers, and where it stops.

What the federal statute says

The Federal Switchblade Act, Public Law 85-623, is codified at 15 U.S.C. Chapter 29. It prohibits the manufacture of switchblade knives and their introduction into interstate commerce.

The statute defines a switchblade as a knife with a blade that opens automatically either by hand pressure applied to a button or other device in the handle, or by operation of inertia, gravity, or both.

“Interstate commerce” is defined narrowly: commerce between a State, Territory, possession of the United States or the District of Columbia, and any place outside of it.

The exceptions

15 U.S.C. § 1244 lists what the prohibition does not reach:

• Common carriers and contract carriers shipping switchblades in interstate commerce in the ordinary course of business;
• Manufacture, sale, transportation, distribution, possession or introduction into interstate commerce under contract with the Armed Forces;
• The Armed Forces, or a member or employee acting in the performance of duty;
• Possession and transportation on the person of a switchblade with a blade three inches or less by an individual who has only one arm.

What federal law does not do

This is the part that gets lost. The Act governs manufacture, interstate commerce and importation. It does not create a federal rule for whether you may own a knife, carry one, carry it concealed, or carry it into a particular building.

Ordinary possession and carry inside a state are governed by state law, and often by local ordinance underneath that. There is no federal blade-length limit for everyday carry, because everyday carry is not what the statute addresses.

Importation is handled separately again, through U.S. Customs regulations at 19 CFR part 12.

Where the charts go wrong

Most published state-by-state guides fail in one of three ways.

They go stale. Several states have changed their automatic-knife statutes in recent years, and a chart compiled once is wrong the moment a legislature acts.

They ignore preemption. Some states bar cities and counties from setting their own knife rules; others do not. In a state without preemption, a knife that is legal statewide can still be prohibited by a municipal ordinance.

They flatten distinctions. Ownership, open carry, concealed carry, restricted places such as schools and courthouses, and rules for minors are separate questions with separate answers. A single green checkmark cannot represent all five.

How to actually check

Work from the statute, not a summary. Most state legislatures publish searchable current code online, and that text is authoritative in a way a retailer’s blog post is not.

Check whether your state has knife preemption. If it does not, check the ordinance for the city or county you are in.

Check restricted places separately — those rules usually sit in a different part of the code than the carry rules.

And if you are flying, the knife question is answered by TSA’s published screening rules rather than by any state statute.

None of this is legal advice, and a genuinely consequential question is worth asking a lawyer in your state. But knowing that the federal statute is about commerce rather than carry removes most of the confusion before you start.

This article was researched and drafted with the assistance of AI tools and reviewed, fact-checked and edited by Leonidas Clark before publication. It is general information, not legal advice. Knife law varies by state and locality and changes; check current law where you are.