What Is A Gravity Knife?

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Gravity knives were invented almost five decades ago during world war II. These knives first originated in Germany and were mainly used by paratroopers.

They helped in entangling themselves from objects like trees while alighting or jumping from airplanes using the parachutes.

A gravity knife features an interesting piece of engineering and has gained many mythological dimensions over the years.

This article will discuss what a gravity knife is, its history, and why these knives are illegal.

What is a gravity knife?


It is a small knife with a blade folded in its handle. A gravity knife opens up the blades from its grip easily through gravitational force or twisting motion.

Its structure’s primary idea is to enable the folded edge to be released and closed simply using one hand.

When the other hand is unavailable or occupied, it is easy to open this knife by flipping the wrist. The knife has a lever that locks the blade closed into its position when it is not in use.

The best part with a gravity knife is that it is pretty small, making it highly portable. This knife is smaller than the size of the palm.

Hence to carry a gravity knife around, you won’t need to have a sheath. You can slip it inside your pocket with a zipper and take it safely wherever you go.

Over time, there have been many variations on the original German gravity knives. One of the most common variations is the eickhorn gravity knife.

This knife features a plastic polymer in the handle, making it moist-resistance and more durable.

The history of the gravity knife

The invention of the gravity knife can be traced back to 1937. The first gravity knife was founded in German during the 2nd world war by the German air force and was referred to as Luftwaffe Fallschirmjäger-Messer.

Its primary purpose was to support the paratroopers as they descend from the airplanes. The military parachuters used this knife in releasing the parachute ropes that got tangled on objects when they were landing.

Before the invention of the gravity knife, most of the knives of that time would require both hands while opening. This mechanism made such knives tricky for the German soldiers to use when their parachutes got tangled on objects.

Moreover, the possibility of being caught by the allied forces before they could free themselves while in such situations was always high. So, that led to the introduction of a knife that could open single-handedly.

Later, the allied soldiers grabbed several Luftwaffe Fallschirmjäger-Messer from German prisoners. When they returned to the United States and the United Kingdom, they named this knife a gravity knife since it applied gravity to open.

Why are gravity knives illegal?

From the invention of the gravity knife in 1937 till 1950, it was legal to carry it regardless of being a military member or an ordinary citizen.

However, after 1950, the popularity of small pocketknives and switchblades among the gang of youngsters was on the rise.

The movies and other media made these knives look like “cool” tools, which further promoted their popularity.

As a result, the lawmakers termed these knives as dangerous, questioning the legality of people possessing them.

In 1954, New York passed a law terming switchblades and small knives illegal. Later in 1958, the law also included the gravity knife as unlawful.

Many other countries followed New York and banned possession of these knives. After that, this law faced severe opposition, especially from law-abiding citizens who primarily used the gravity knife as a utility tool.

However, there were many arrests for people who were found in possession of these knives and were subject to criminal penalties.


A gravity knife is a handy tool that is easy to carry and use. Up to date, this knife remains a useful utility and tactical tool used by many people.

Although these knives are illegal to carry along in some states, there is a lot you can do with them at your home.

Therefore, it is advisable to check the laws regarding these knives in the state you live in before you buy, carry, and use your gravity knife.