Switchblade knives are a type of knife which opens or closes automatically by pressing a button, usually installed on the handle. There is some disagreement as to whether switchblades and automatic knives are synonymous — that is, one device cannot be both automatic and switchblade. Automatic knives don't require the user to press any buttons to activate the blade; switchblade knives do. 

Types of Switchblade knives come in many different styles and sizes, but generally have one thing in common: when pressed against someone's skin (or "plunged" into someone), they can easily cut their entire body from head (top) to feet (bottom). Switchblade knives are not legal to carry in public areas in the United States.

A switchblade is a knife with a folding or sliding blade contained in the handle which can be opened by means of a spring mechanism. A switchblade is opened by flipping the edge out, usually by pressing a button, lever, or another device on the knife's handle. Switchblades may also have a locking mechanism to hold the blade open. The term "switchblade" generally refers to automatic folding knives instead of manual folding or non-folding knives such as traditional pocket knives and jackknives.

Types of Switchblade Knife

Switchblades, or automatic knives, come in various shapes and sizes. In fact, there are 7 different major types of a switchblade knife: side openers, jackknifes, out-the-fronts (OTF), in-the-hilts (ITH), toothpick knives (TPK), balisongs (butterfly knife), and double action.

Understanding the difference between these types is very important, especially in places where switchblades are illegal. Each type has its own specific characteristics and each one is used for a specific purpose. They are not all designed to flip open easily and quickly with one hand, they don't all feature a button or spring-assist for this purpose, and there are models that don't even have a "safety" of any sort. Below is a quick description of the seven major types of switchblade knife:

1. Side Openers

Side openers are some of the most popular and most common types of automatic knives in existence. Most ratchet knives you will find out there fall into this category. They feature a set of two blades that are completely perpendicular to one another. They open with one hand and lock up easily once they are in the opened position. They usually have an edge or bevel on the front of both blades for added safety, and may also have a protruding finger guard on the handle to keep your fingers safe.

2. Jack Knives

Jack knives are another common type of automatic knife. They are very similar to side openers, but instead of being completely perpendicular, they are slightly out-of-parallel. This means that once you pull back on both handles simultaneously, they will snap together at a 45-degree angle (perpendicular) almost like two large scissors. It is very rare to find one that opens with one hand, but there are a couple of exceptions.

3. OTF

Out-the-front (OTF) knives are similar to side openers, except they feature two large blades. The blades are usually mounted parallel to one another and do not have finger guards. Out the Front knives can be flipped open with one hand and locked up easily, but can also be flipped out of the way by pulling back on both handles simultaneously so the user can operate them with just one hand. There are several models of this general type that also feature blade "locks" as well, which allow the blade to remain in place even when it is locked (which is great for public carry).

4. ITH

In-the-hilts (ITH) knives are types of switchblade knives that are new to the market. It features two blades mounted on both sides of a double-action handle. To open it, you can: 1) pull back on both handles at once, causing the blades to swing open like a rapid butterfly knife or 2) flip open the knife and then press down on the spring mechanism with your fingers to cause them to swing down and lock into place. 

The main reason this type is so new is that it has only been legal in the U.S. for about five years now (since Congress passed the Folding Knife Act of 2009). It is only now that knife manufacturers are starting to offer them, and there remains a lot of confusion about how they work as well as no real "training" methods for law enforcement officers to learn on how to legally handle such cool knives.

5. TPK

Toothpick knives (TPK) are from the same category as balisongs. They are often mistakenly referred to as balisongs, but they differ in more than just name. They are mostly very similar in their construction but have different basic features. Some TPKs feature a spring-assist feature so the knife will snap out of the closed position with one hand instead of requiring both hands as most balisongs do.

6. Folding Knives

Folding knives can be your switchblade knives. Some knives feature a push button and you can open the blade after pushing that button. The blade remains hidden unless you open it. As you push the button, the blade comes out from the side of the handle. After using it, you can fold the blade back into the handle.

They are usually much lighter than most other switchblades, due to not having a handle for things to be attached in the first place. Some folding knives are big enough that you can wear them as a belt buckle or have several on your keychain without anyone ever knowing you're carrying one unless you want them to know.

7. Double Action

Double-action knives are automatic knives that feature a mechanism that allows the user to open and close the knife with one hand. These types of switchblade knives are not legal in some areas (like New York City, for example), but may be legal in other places. They usually feature a slider or wheel that the user must press down on both sides simultaneously to release the blade. The blade remains in place until you press down on both sides of the mechanism again.

Other Types of Switchblade Knives

I am an avid knife collector and I have quite a few types of switchblade knives. In my opinion, the advantages of switchblade knives that one would not expect make them more desirable than simply fixed knives. Let's take a look at some of these advantages.

  • Manual Spring Switchblade Knife

The primary advantage of switchblades with manual springs is how easy they are to carry when compared to a fixed-blade knife. This is because they are able to be locked open with no risk of accidentally closing it while in use or carrying it without worrying about closing it on something by accident.

The secondary advantage to opening manually is the unique stiletto-like feature of switchblades that can be used in self-defense. They have pointed weapons that can be stabbed into someone without the risk of accidentally stabbing them back.

  • Automatic Switchblade Knives

Automatic knives in general have always been popular among those who like to hunt or just want a reliable knife for home and personal use. Automatic knives are also popular among those who like to carry their knives in their pockets and have a fear of losing them. The automatic function is often referred to as a safety lock, which prevents the knife from opening by accident.

The primary advantage of automatic knives is their versatility. They can be used to perform many tasks including slicing, fileting, skinning and even burning small game. The secondary advantage with automatic knives is the possibility of it being taken apart into a smaller size. This allows one to carry more knives on their person and not have to worry about them accidentally closing.

  • Double Action Switchblade Knives

Double-action switchblade knives differ from most other switchblades in that the blade itself automatically opens by depressing two buttons simultaneously on the handle of the knife upon release of the thumb stud. Some people refer to a double-action knife as a flick-knife. Flick knives are illegal in Canada and the United States, but are often seen used for self-defense purposes (more on point below).

The primary advantage to these types of switchblade knives with double action is the ability to open them without having to use both hands. The secondary advantage with double-action knives is that they can be held more securely when opening since both hands do not have to be folded together (as they would be with an ordinary switchblade). Some people call this type of switchblade a "flick-knife".