No, Gravity knives are not illegal in the United States, at least not in every state. Yes, it mostly depends on which state you live in because the laws surrounding these knives are enforced by the state laws. Sure, there is no nationwide ban, but there could be a state-wide ban on Gravity knives. Let’s talk a bit more about that.

What’s a Gravity Knife?
A gravity knife is basically a folding knife that you open by releasing the catch and then either letting gravity or a quick flick of the wrist do the opening. It is different from a normal pocket knife in that the blade is not pulled out by hand, but rather it is quickly swung open and locked.
These knives were first introduced in a time period of World War II. The soldiers and paratroopers were using them to free their tangled parachute cords with one hand. At present, these kinds of workers, namely the construction workers, rescuers, and naturists, are still using them because of their quickness and practicality.
A Quick Look Back
In the period after WWII, gravity knives were widely accepted by the general public. However, from the 1950s onwards, films and media began associating them with gang activities, although the majority of users were workers. Sure enough, later down the line, this perception of the weapon made legislators classify them along with switchblades and other automatic knives.
As a result of that very thing, the Federal Switchblade Act of 1958 prohibited the selling or shipping of gravity knives, along with other switchblades, across state lines. However, possession of such a knife was not illegal under that law. After that, states created their own regulations, and that’s when the situation became confusing. Certain states prohibited them completely, while some states were indifferent.
What the Federal Law Says
It is not prohibited by any federal law to have a gravity knife in your possession. Plain and simple! The Federal Switchblade Act regulates only the sales and transport that is across the border. Therefore, owning one is not a problem when considering the whole country. However, the regulations of the states are still significant since every state makes its own decision. We can analyze it by state.
Where They’re Banned
States like California, New Jersey, Massachusetts, Illinois, and Delaware have either banned gravity knives or put tight limits on them.
- In California, anything over a two-inch blade is treated as a switchblade.
- In New Jersey, carrying one without a valid reason can count as a fourth-degree crime.
- In Massachusetts and Illinois, even having one at home can cause problems.
Where They’re Legal
Quite a few states do not have any issues with gravity knives. After the court case, New York made them legal in 2019. Besides New York, the states such as Texas, Florida, Oregon, Arizona, Colorado, Ohio, Michigan, and Hawaii permit gravity knives in everyday situations like, it is only advised not to take them to schools or government buildings.
Other than that, just know that Hawaii even dropped its ban in 2024, which shows how things are changing fast.
The “Depends on the Situation” States
Gravity knives in some regions are considered a gray area kind of weapon. These states have not prohibited them, but employing one in an improper manner may cause you to get into trouble.
Michigan and Rhode Island can be taken as instances of such states, where these knives are not criminalized; however, it is illegal to carry one if you intend to use it for a bad purpose. Moreover, the regulations of a particular city can still have an effect on you. For example, carrying a gravity knife is permitted in New York State, but it is prohibited in NYC on buses or subways.