Gravity knives have been around for more than 50 years, yet they continue to attract attention and controversy, even in recent years, due to questions surrounding their legality. They were invented during World War II in Germany and spread to the United States and the United Kingdom during that time.
What are gravity knives? How do they work? Are they legal? This is your guide to the world of gravity knives.
The gravity knife was invented out of military necessity during World War II to help German parachutists untangle themselves from their rigging. The knife’s popularity spread to other countries during the war.
Up to 1950 it was legal in the US to carry the knife for personal and military uses. After this period, gravity knives, switchblades, and other small pocket knives became increasingly popular among youth street gangs and laws were introduced to ban or restrict their use.
The US federal Switchblade Knife Act 1958 prohibits the importing, manufacture, and commercial sale of switchblade knives. The Act also prohibits possession of automatic knives or switchblades knives on federal lands. However, the Act does not prohibit ownership or carrying these knives within state lines.
Knife laws have also been introduced at a state level. New Your State passed a law in 1958 making switchblades, gravity and other small knives illegal. A number of states have also tried classifying lock-blade folding knives as gravity knives.
Though New York was the first state to ban these knives, it wasn’t the only one. Some states followed their example, believing small pocket knives to be too dangerous for individuals to carry around.
Legislators advocating for bans thought that only gang members and criminals carried these knives. But the most common arrests have been citizens using these knives as utility tools.
To reduce grey areas, some states have amended their laws while states such as Colorado have repealed their bans on switchblade and gravity knives.
According to the American Knife and Tool Institute, state knife laws have been changed across the country. In most states, citizens can now carry auto-open knives such as automatic, switchblade, or switch knives.
In 2019, a federal District Court also ruled that the New York ban on gravity knives was too vague, making it unconstitutional. New York State has now overturned its ban on gravity knives. However, switchblades, pilum ballistic knives, and knuckle knives including trench knives are still banned in that state.
How Do Gravity Knives Work?
During World War II, German paratroopers would sometimes get tangled in their parachutes as they landed. Most knives at that time required two hands to open, which made them difficult to use in this situation. There was also the risk that they could be caught by Allied forces before they could free themselves. This led to the invention of a knife that could be opened quickly with one hand.
When Allied soldiers took these knives from their German prisoners, they brought them back to the U.S. and UK, calling them gravity knives. This is because the knife literally uses gravity to open. It simply falls open when pointed towards the ground. A lever locks the blade in place when not in use, and can be flipped back into place after the knife has been opened, preventing accidental slips. This makes the gravity knife one of the easiest knives to open, use, and carry.
Uses of a Gravity Knife
Originally, gravity knives were used to free paratroopers from their tangled parachutes. Though most soldiers would have also been carrying a fixed hilt combat knife, it was bulky and not ideal for parachute drops. The gravity knife was small and could be carried inside a pocket, making it perfect for the drop itself and any combat that might occur afterward.
There were also attachments that added new uses, such as the marlinespike and awl. The marlinespike was designed for marine ropework and became useful for untangling knots. The awl could be used for piercing, prying things open, and fixing jammed weapons. These attachments folded into the knife.
Is a Gravity Knife a Switchblade?
Gravity knives and switchblades are very similar, which often leads to gravity knives being categorized as a type of switchblade. There are differences between the two, though.
The main difference is the operation of each knife. Both knives keep their blades tucked inside their handles. However, they use different mechanisms for opening. Gravity knives feature a locking lever and fall open due to gravity once this lever has been moved. Switchblades, on the other hand, are operated by a spring inside the handle. When a button is pushed, the blade is released automatically.
There are other knives that are similar to gravity knives in addition to the switchblade. These include butterfly knives, out-the-front (OTF) knives, and penny knives.
Types of the Original Luftwaffe Gravity Knives
There have been variations on the original gravity knife since World War II, as well as knives that are similar. The various types of gravity knives include:
- Type I LGK. This was the earliest version of the German Luftwaffe Gravity Knife (LGK). It was sometimes also called the Luftwaffe Fallschirmjager-Messer and was designed to help paratroopers free themselves from tangled parachutes. It was made by three different manufacturers in Germany from 1937 to 1943 and had five variations. It featured wood scales on the handle and was strictly for cutting parachute ropes.
- Type II LGK. This was the next evolution of the German LGK during World War II, manufactured by two companies with five variations. It was made during two periods – from 1943 to 1945, and again after the war ended, from 1950 to 1965. This new gravity knife included takedown features, making it a convenient addition to bulky combat knives.
- Type III LGK. This knife was made after the war, from 1955-1961. It was nicknamed the “trap door” gravity knife. The knife proved to be unreliable, so the Type II design was used until the introduction of Type IV.
- Type IV LGK. Manufactured from 1972 to 1984 by three companies, including Eickhorn, this knife replaced the ineffective Type III knife. It was very similar to the Type II, with the only difference being the materials used in the handle. The Type IV featured plastic polymer in the handle, rather than the wood scales of the Type I and Type II knives. This made the handles more durable and resistant to moisture. German soldiers were still carrying them until about 2017.
- Type V LGK. This is the most recent model of the LGK. It began production in 1979 and is still being made today, under the designation LL80, by Eickhorn. It is smaller than previous models and easier to manufacture, due to the fact that it uses fewer parts. This gives it a simple manufacture process and makes it more cost-effective than previous gravity knives. It was obtained by the Swiss Air Force in the early 1980s and is still carried by German soldiers today.
- A British version of the gravity knife produced in England. The British government decided to create their own gravity knives after confiscating Type I knives from German soldiers. Manufactured by George Ibberson and Company, out of Sheffield, it was used almost exclusively as a secondary combat knife by members of the Special Operation Executive and other wartime units. It featured a handle made of smooth wood or sometimes plastic, as well as features identical to those found in the German Type I knives, including a locking mechanism, gravity-deployed blade, and folding spike or awl.
Gravity knives have a long history, going back to the chaos of World War II. They have had many variations and changes over the decades since then but still remain as useful tactical and utility knives.
Gravity knives are similar to switchblades and are often classified as such. They have a very appropriate name since they work by falling open when exposed to natural gravity.
Though these knives are useful and convenient, there are bans or restrictions to carry in some states so caution must be exercised.
Always know the laws in your state, as well as local city and county laws, as they apply to gravity knives. If caught carrying one illegally, or carrying across state borders, you could be arrested.