What Is a Gravity Knife? Features and Illegality Issues

Gravity knife lies in the category of multipurpose knives which can be used for other purposes besides cooking. It is a tiny gadget with a blade folded in the handle and release easily by hand motion under gravitational force. The main purpose of easy release gravity knife is to allow its use with one hand when the other one is busy with just a flip of a wrist. 


The robustness of the gravity knife has made it an important tool for carpenters, paratroopers, and wood hunters. Unfortunately, due to misuse by some wrongdoers, the gravity knife faces a legal ban and is only allowed in some states under government rules and regulations. 

The origin and Evolution of Gravity Knife

During World War II, the gravity knives were designed keeping in view the needs of paratroopers and airplane crew members to release their parachutes tangled in trees or other objects during landing. Hence, they were made in such a way to release quickly with only one hand and light enough to use easily. 

The first knife was made by the German air force named Luftwaffe Fallschirmj√§ger-Messer for German paratroopers as all knives needed two hands to use during that time. Moreover, in war zones, the risk of catching up by allied forces if parachutes get entangled was always high, so a knife that can be open with one hand to release themselves was introduced. 

Oerla Fixed Outdoor Knife

Snake Eye Tactical Knife

Steinbrucke Tactical Knife

Features of a Gravity Knife

  • It has a blunt-spear point blade embedded in a metallic frame fitted onto a wooden handle
  • A lever attached at one end of the knife can easily be flipped to release the blade from the frame. Under the force of gravity, the blade opens to the full extent. 
  • Closing the blade is as easy as opening it, when you flip the lever back, the blade is easily withdrawn to its original position.
  • The high carbon blade is very sharp and cut the woods with just once slicing movement.
  • You can say it is a small pocket knife with the powers of an ultra-sharp knife. 
Features of gravity Knife

Types of Gravity Knives

Gravity knives are classified into two types based on blade opening mechanism which are:

Standard Gravity Knife

It is quite similar to a folding knife which has a hinge at one end. This knife is opened by pressing the lever attached at one side and flipping the wrist in the rear hand direction. The lever is attached to such knives to protect the blade and precludes its snaky movement on the hinge. By flipping out the inertial movement brings out the blade while the released lever helps to retain the blade in an open position.

Out the Front (OTF)

out the front gravity knife

In this type of gravity knife, the blade is withdrawn in a hilt and comes out straight. The lever is attached over the top of the hilt in out the front knives. If you want to open the blade you need to pull out the lever riving the hilt in a forward direction, move your hand back and glide the blade forward locking it by the lever. 

Some other types of gravity knives are also available in the market originated from different countries. The first one made by Germany was modified by George Ibberson & Co. of Sheffield, England creating a British version of a gravity knife. It was designed to be used as a secondary combat weapon. The only difference was the handle which was made of smooth wood or plastic. 


Moreover, some other knives such as Switchblades are also commonly mistaken as gravity knives. But switchblades are automatic and gravity knives are manual. In these knives, the blade is placed inside the handle, and to open it you have to push a button attached to a spring.

Similarly, butterfly knives are also considered gravity knives. But they differ in the blade opening principle which relies on hand movement instead of gravitational force. In these knives, the handle is flipped open like a butterfly that is divided into two parts. To open the handle, the two parts are moved apart from each other revealing the knife within. 

Where to use a Gravity Knife?

  • Gravity knives are best used for combat purposes, not as fighting knives, but wood cutting or releasing parachutes from trees in tricky situations. 
  • Some of the gravity knives come with attachments like awl or marlinespike. These attachments are helpful in marine ropework to untangle the knots. The awl attachment is used in piercing, prying open, and opening the blocked weapons.
  • As the blade is made of high carbon steel so you can also use it for cutting purposes. Especially when you are out in the woods, a gravity knife can be a versatile tool to help you move through the woods and cook food for yourself.

Check our article on Electric Fillet knife VS Regular to compare fillet knives from various big brands. 


You can also look into our article on best fish filleting electric knife for your next fish party.

Regular Knife Vs Electric Fillet Knife

Gravity Knife Ban Lifted

The misuse of gravity knives by some law-abiding citizens resulted in a ban on these knives in some states. In 1958, New York passed a law to ban the use of dangerous weapons and in years between 2000 and 2012, gravity knives were thrown in this list. Over the years, the law created soft corners for gravity knives but still, they are illegal to carry on the subway system. Knives are one thing that interests you then do consider smith and wassen knives

If you want to buy or carry a gravity knife with you, just have a look at the law in your state before buying. Some states have banned them but some states have lifted the ban but with some regulations. 

Other than Gravity Knife, Ballistic knife is also considered illegal in the US.

Here we have created a short introduction including, what is the ballistic knife?, its uses, and is it legal in the US?. 

Hope you find the article useful…

what is ballistic knife - is a ballistic knife legal

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