What is a Gravity Knife? Where to Buy One ?

(This site is reader-supported. When you buy something using retail links on our articles, we may earn a small commission. As an Amazon Associate I earn from qualifying purchases.)

It has been more than five decades since a gravity knife was invented. Still, it is a controversial topic in the world of knives. So, what is a gravity knife? Is it legal? How does it work? What are its uses? Read on to get answers to these questions.

What is Gravity Knife?

A gravity knife is a small tool with a blade folded in the handle, released due to hand motion and gravitational force. The primary purpose of its structure is to allow releasing the folded blade with just one hand. Thus, it is easy to open this knife with just a wrist flip when the other hand is busy.

A gravity knife is a common tool that several tradesmen use almost daily, ranging from dock laborers to carpenters. Sadly, these knives have been in the governance of legal rules and regulations, due to which they have witnessed the banned status. So, yes, people with these knives were arrested due to the strict laws.

However, at present, the good news is that a recent struggle for knife owners is all set to make the gravity knives’ possession and use legal, at least in the state of New York. This will spare knife owners from an unjustified arrest.

History of Gravity Knives

Kappmmesser gravity knife
Source: Bammbuss

The gravity knife was primarily designed to aid paratroopers and crew members of airplanes in liberating themselves from their parachutes that got entwined in objects such as trees at the time of landing. Thus, it was made in such a way that just one hand could open as well as use it.

Originated in Germany, these knives were introduced during World War II. During the war, the German paratroopers would sometimes get tangled in their parachutes. In addition, almost all knives of that time needed two hands to open. This mechanism made it tough to use these knives in this situation.

Further, the risk of being caught by the allied forces was always there before becoming free from the entanglement. Thus, a knife that could open with just a hand was introduced.

Later, the allied soldiers grabbed them from the German prisoners brought to the United Kingdom and the United States. They termed these knives as gravity knives, as they used gravity to open. A gravity knife was indeed designed before the invention of an affordable and reliable switchblade knife.

Made by the German air force, the first gravity knife came in 1937. It was named Luftwaffe Fallschirmjäger-Messer.

If you think German Paratroopers used the butterfly look-alike Pantographic knives, read this article discussing Paratrooper Vs. Pantographic knives.

How Does Gravity Knife Work?

A gravity knife relies on inertia and the gravitational force to release its folded blade. When it was made, the concept of spring-driven knives was not so famous. So, there was no chance that a spring mechanism was included.

While the fixed combat knife can be opened with one hand, it is bulky and is likely to get separated from its sheath at the time of parachute landing. However, a gravity knife is small enough to fit safely inside a pocket with a zipper, like any best pocket knife.

The blade falls open when the knife points towards the ground. When not in use, a lever keeps the blade intact in its position by locking it. Once the blade is out, you can flip it back to keep accidental slips at bay. This is how a gravity knife is among the easiest knives to open, carry, and use.

Even today, a gravity knife’s blade with a blunt-spear point remains folded in a frame made of metal. This frame is inside a wooden handle. As you flip the lever residing on a side, the blade comes out from the frame and opens completely due to the force of gravity.

Closing the blade is also a breeze. Just flip the switch again, which releases the blade’s lock. The blade gets unfolded by flipping the hand in the frontward motion, while otherwise, the switch is released to protect the blade in the frame.

Compared to a standard folding knife, a gravity knife is relatively alluring. This is because you can open and use it with just one hand. The former knife’s closing mechanism is usually too stiff to be flicked with just one hand.

Types of Gravity Knives

In terms of how the blade opens, there are two kinds of gravity knives, which are as follows:

  • Standard: It is exactly like a folding knife with a hinge on one side. For opening such a gravity knife, it suffices to press the lever on the side and flip the wrist in a rear-handed manner. This lever secures the blade and prevents it from winding loosely on the hinge. The flick’s inertia takes out the entire blade while releasing the lever retains the blade in its open position.
  • Out the Front (OTF): This is the design in which the blade withdraws in the hilt. Again, it is made to glide out straight. This time, the lever is over the front of the niche atop the hilt. You only need to pull the lever to drive the hilt forward, take the hand back, and glide the blade forward where the lever locks it.

There are some more types to consider. Once the German gravity knife became famous, its British version was soon introduced in England. This knife was designed to work as a secondary combat weapon.

It was quite like the German knives. However, there is a difference in handles, which can be of smooth wooden or plastic.

Even a butterfly knife is thought to be a gravity knife. However, there is a difference. This knife depends on the movements of your hand, not on the gravitational force.

Further, in the case of this pocket tool, the handle has two parts that you can flick just as the butterfly’s wings. You need to move the two parts away from opening the handle.

One classic example of a modern-day gravity knife is Paragon Warlock in the picture below.

paragon warlock gravity knife

Similarities of Gravity Knives with Other Knives

Switchblades and gravity knives are often interchangeably used, as they are similar. Some people consider a gravity knife to be a switchblade type. However, they both are different.

The main difference is how they both operate. Both knives indeed have their blades inserted inside their handles. Nevertheless, the opening mechanisms each of them follows are different.

Gravity knives employ a locking lever and open due to gravity after moving the level. On the contrary, switchblades or OTF knives work with the help of spring present in the handle. Pushing a button automatically releases the blade. Thus, unlike gravity knives, switchblades are automatic.

Several latest folding knives come with a pin close to the folded blade’s side. You need to flick this pin to open the knife with just one hand. This means they are the same as gravity knives in terms of functionality. Nevertheless, unlike gravity knives, these knives come with stiff hinges. In other words, a user of a gravity knife can more quickly draw and open the knife than a user of a folding knife having a pin.

Where to Buy Gravity Knives

Blade HQ, ViperTec offers gravity knives produced by Paragon and AKC. Paragon has Warlock, Pheonix, and Dredd models, and AKC has the Gravit-E model available for purchase.

Uses of Gravity Knives

In its early days, gravity knives were used to help paratroopers while alighting or jumping from airplanes to avoid being trapped in a tricky situation. Although they were not designed as fighting knives, gravity knives were also used for combats.

These knives were also available with different attachments such as an awl or marlinespike. The marlinespike is usually used in marine ropework, mainly to untangle knots. Similarly, the awl is useful for prying open, piercing, and fixing blocked weapons. All these addons are folded into the knife.

The lawfulness of Gravity Knives in the Past

Right from the invention during World War II to 1950, gravity knives were legal. It was alright to carry them regardless of whether they were ordinary people or military members.

After 1950, gravity knives and small pocket knives, including switchblades, became more popular amongst the gangs of youngsters. Even the media and movies promoted them as cool tools to have.

The lawmakers questioned these knives, as they were also dangerous. This made the city of New York pass a law in 1954 to make small knives and switchblades illegal.

In 1958, even gravity knives became part of this law. Well, New York was not the only state to prohibit the use of these knives. A few states, such as Colorado, had tried to include other knives in this banned category by categorizing them as gravity knives.

Many states soon started believing that small pocket knives are risky for people to carry wherever they go. Also, several legislators believed those carrying these knives are likely to be a part of some gang and criminal groups.

However, it was shocking to know that the numerous arrests that followed the successful establishment of laws were those citizens who had them as utility tools. Thousands of citizens were arrested in New York between 2000 and 2012. Almost all of them carried the knife for their job. They were unaware that the law prohibited these tools.

Once the awareness spread, the new laws faced great opposition from the law-following citizens who carried these tools for utility purposes and not for any criminal motive. Nevertheless, most of these laws were never revoked. Thus, they are still enforced.

Because the definition of small pocket knives was not clear, even the citizens using these knives have been arrested as well. Although many states have now amended the legal directive frequently to clarify the definition, the arrests are still happening. Still, the law of carrying gravity knives is constantly under the amendments.

Are Gravity Knives Legal?

Paragon Pheonix
Paragon Pheonix

However, the likelihood of revocation of laws for gravity knives is high soon. Again, this time, the source of motivation is the city of New York.

In March 2019, the related law in New York for banning gravity knives was declared as too vague, due to which it was proved to be unconstitutional. A federal district court declared this.

This inference forced the state government to legalize gravity knives as utility knives in May 2019. While you can now carry these knives legally in New York, it is still illegal to do so in other states.

However, the same state that initiated the prohibition of gravity knives has now revoked the law. However, the knife is still prohibited on the subways. Nevertheless, this is likely to persuade other states to reconsider their laws regarding gravity knives to reword them to allow their citizens to carry them.

States like Ohio are already reconsidering their laws. Switchblades and gravity knives in most states are indeed illegal even today. However, you need to understand that each of them has its perspective to view the issue uniquely. This means that their laws also tend to differ accordingly.

In simple words, the types of knives looked upon as forbidden and places where they are prohibited vary from one state to another. Thus, it is wise to check the state’s laws in which you are residing or traveling before deciding whether to buy and use a gravity knife.


Gravity knives are designed to be opened with just one hand, due to which they are popular amongst people engaged in a trade or normal chores requiring knives. Although they are now allowed in New York, they are banned in other American states. Thus, it is wise to check the laws and buy, carry, or use gravity knives.