What is a Gravity Knife?

A gravity knife is a type of knife where the blade is contained within its handle, and it is opened by the force of gravity. This method of opening and closing the knife allows for it to be performed one-handed.

How Do Gravity Knives Work?

Gravity knives use a button or a mechanism such as a fulcrum lever to open or close the blade and deployment is either side-folding or out-the-front, or OTF.

Most of the military-issued gravity knives used a design where the blade locks into place but any other variations do not mechanically lock the blade in the open position. These types of gravity knives use friction to hold the blade against the handle.

Are Gravity Knives Illegal?

In some states and cities in the United States as well as Canada and the United Kingdom, gravity knives have been criminalized along with automatic knives or switchblade knives. Some of these jurisdictions prohibit carrying what they consider to be a gravity knife. However, many of them criminalize the mere possession of such a knife.

The problem is that state lawmakers, district attorneys, and police officers have changed the definition of a gravity knife as written in the penal laws to use it against most commonly carried pocket knives that are not opened due to the force of gravity.

In some areas, law enforcement officers may perform what is known as a “wrist flick test”. In instances such as these, if an officer takes a person’s knife and they can open it with a flick of the wrist; the knife is considered a gravity knife and therefore a deadly weapon. Always be careful in any area where there may be a gravity knife statute as mere possession can be considered a felony if the knife in question meets their definition of a gravity knife.

Why Did Gravity Knives Become Controversial?

Gravity knives earned a bad reputation as being only suitable for a knife fight or being the tools of hoodlums and criminals. Yet the truth is that gravity knives were actually designed and invented at the turn of the twentieth century to allow people to more easily open pocketknives without the use of a spring. They were considered a cheaper alternative to switchblade or automatic knives Some were designed to be used by paratroopers in case they needed to access a knife quickly to cut away a failed parachute or cut themselves loose of shroud lines if their parachute hung them up in a tree or other obstacle. Wartime budgets often made it so that the militaries in question needed a cheaper alternative to an automatic knife.

A false moral panic was created half a century later in November of 1950 by a Woman’s Home Companion magazine author in an article titled “The Toy That Kills”. According to police research from the same time period, gravity knives were not found to be used in a significant way on the streets of major cities. They just were caught under the umbrella of switchblade knives in various laws restricting their use as a means to frighten people that are very easily frightened.

In recent years, many of these knife laws are being reversed or repealed in many areas of the country. In certain locales, these laws will most likely never be repealed without intervention by a federal judge or the Supreme Court of the United States.

For example, New York City had numerous laws which criminalized carrying certain knives or simply owning one in the home. This included laws against a certain blade length, automatic knives, butterfly knives, ballistic knives, double-edged knives, and of course gravity knives.

The problem was that police officers would arrest people and confiscate their knives if they had an assisted opening mechanism or if it were a simple box cutter or razor knife under the presumption that they were gravity knives defined by the city’s penal code.

Public defenders in New York City were becoming overwhelmed with cases where their clients had committed either a minor infraction or simply no other crime other than the possession of what a police officer considered their pocket knife to be a gravity knife.

However, in March 2019, a federal court declared New York City’s statute on gravity knives to be unconstitutional and vague. In May of that same year, gravity knives were legalized or decriminalized in New York City with regard to mere possession. However, the city still has prohibitions against transporting or carrying certain types of knives.

What’s The Difference Between a Gravity Knife and a Butterfly Knife?

While the blades of gravity knives are released by pressing a button, trigger, or lever; butterfly knives require turning and flipping of the knife’s handle in order to use the blade. In certain areas like New York City, butterfly knives were at one time classified as gravity knives and are considered dangerous weapons.

The biggest difference between the two types of knives is that the butterfly knife requires a degree of skill and manual dexterity in order to open or close the knife properly and safely.

Knives You Can Purchase from BladeOps

Modern gravity knives are a bit of a rarity these days as manufacturing methods have become much easier and cheaper to make due to the use of CNC machinery, 3D printing, and other methods. Gravity knives of old were considered a cheaper alternative that was easier or cheaper to manufacture.

BladeOps offers a huge selection of knives that are easy to open without using the force of gravity. These alternatives include butterfly knives, automatic knives, and classic fixed-blade knives.

Butterfly Knives

Although sometimes considered to be gravity knives in very few jurisdictions, BladeOps has a good-sized inventory of what is typically known as butterfly or balisong-type knives.

These knives are manufactured by companies such as Bradley Cutlery, Bear & Sons Cutlery (Bear Ops), Boker, Kershaw, and even custom designs using high-end materials like titanium and carbon fiber as well as premium steels by MaxAce.

They literally have butterfly knives to fit every budget as well as training versions of these knives so that knife owners can practice with them in order to safely develop their skills with regard to opening and closing the knife without fear of injury.

 Automatic Knives

While a butterfly knife may not be everyone’s cup of tea for a one-handed opener. Blade Ops also offers automatic knives that are opened by pressing a button. This action utilizes a spring contained within the handle that propels the blade into place when ready to use.

Automatic knives come in two variations: out-the-front (OTF) and side opening. BladeOps carries a full line of both types by manufacturers such as Boker, Kershaw, Microtech, Piranha, Smith & Wesson, Bear & Sons, and Protech as well as many others.

Be aware of your local laws regarding ownership, transportation or carry of these types of knives before ordering.

Fixed Blades

Of course, the fixed-blade knife is an often overlooked alternative to gravity knives, automatic knives, butterfly knives, or folding knives. While it is often more convenient to carry a folding knife in a pocket or clip to a pocket, a fixed blade is ready to use quicker than many of these designs.

Fixed blades are the oldest type of knife and go back to the dawn of human history as mankind’s oldest tool. While many traditional fixed-blade knives are carried in a sheath on a belt and may alert people to the fact that you have a knife on your person, a number of manufacturers are offering small, fixed-blade knives in sheaths that allow them to be carried inside the waistband or inside the pocket as a carry mode of discretion.

BladeOps offers an unbelievable selection of fixed-blade knives from companies such as Boker, Columbia River Knife and Tool (CRKT), Gerber, Heretic, Microtech, Tops, and many others. With literally thousands of models to choose from. A good fixed blade may be a smarter alternative to a gravity knife or any other type of one-handed opening blade.

As is the case with butterfly knives, gravity knives, or automatic knives, check your local laws regarding fixed blade knives and legal blade length laws or laws about the carry of these knives.

True modern gravity knives may be a rarity or a complete oddity in this day and age, but there is a huge variety of better-made alternatives that should not require you to weave through the legal system for your everyday carry knife.