Knife Lock Types

Why is the Knife Lock Type Important?

One of the most important aspects to a folding pocket knife is the locking mechanism. If you open a folding knife in order to use it, you want the blade to lock open and remain in that position so you can perform your cutting tasks safely, without fear of the knife closing on your fingers.

Let’s take a look at some of the most common lock designs on the market today.

Types of Knife Locks

Knife locks are almost as diverse as the types of blade styles that are out there. Some will be familiar to everyone and a few may be new to you.

Lock back

Lock Back knives are a popular style that have been around for close to 500 years according to most historical source material. It works on a simple principle: a bar fits across the spine of the blade with a spring beneath it. Pushing down on the bar to unlock the knife disengages a rivet locked against a detent which allows the blade to open quick and easy and close just as quickly..

As simple as that may sound, it required a high degree of fitting so the lock would hold under use. As a result, these were expensive knives and therefore not very popular until the 1950s when Buck Knives released the Model 110 at an affordable price.

Also referred to as Back Locks and in some cases Mid Locks when the lock is positioned in the middle of the handle as opposed to near the bottom of the handle.

Liner Lock

The Liner Lock is a locking mechanism that relies on a lock cut into the liner of the knife’s handle. It was designed over 100 years ago but refined and perfected by custom knifemaker Michael Walker in the 1980s.

It is one of the most common locking systems found on modern tactical folding knives and because it can be opened faster than most other locking type knives it revolutionized the knife industry. It is the hallmark of Emerson Knives for a locking mechanism.

Most liner locks use a titanium locking bar and a hardened steel back stop. Some liner locks rely on a steel liner. The thought here is that while titanium is stronger and lighter than steel, one side will wear out sooner between the titanium liner and the steel blade. Using a steel liner is designed to address this.

Frame Lock

A frame lock or integral lock is an evolution of the liner lock where the entire locking side of the knife folds over to lock the blade open against the stop pin. It was invented by South African knifemaker Chris Reeve in the 1990s for his Sebenza model. Knife manufacturers such as Kershaw, Zero Tolerance and Strider use the framelock design on many of their models.

Because of the amount of titanium in most frame locks, these knives tend to be a bit more expensive. Some budget conscious models are released using other metals than titanium for the lock side of the knife, such as stainless steel.

Many knife experts feel that the frame lock is one of the strongest lock types out there and say that some knives lock up as sturdy as a fixed blade knife.

Compression Lock

The compression lock was designed by Spyderco Knives in the 1990s. It resembles the face of a liner lock, but it is found on the rear of the knife’s handle like a lock back. The locking mechanism utilizes a leaf spring in the rear of the handle that wedges between a ramp on the tang of the blade and the anvil pin (or stop pin).

Axis Lock

The Axis lock was developed by custom knifemakers Bill McHenry and Jason Williams in the 1980s. Benchmade Knives bought the patent to use the lock on their knives and for 25 years, they held the patent which prevented other manufacturers from using it.

Now that the lock design is an open source design with the expiration of the patent, other manufacturers are putting a version of it on their knives. These manufacturers include CRKT (Columbia River Knife and Tool), Gerber and Spyderco.

The Axis lock works by means of a sliding spring-loaded bar that moves back and forth in a slot found in each of the two liners. The lock engages a ramp on the rear tang of the blade when it is opened. Essentially the bar offers full support placing the tang of the blade between the lock bar and the stop pin.

A similar design is the Arc lock offered by companies like SOG Cutlery and Boker Knives.

Button Locks

A button lock is commonly found on automatic knives, gravity knives and flick knives. It is also known as a plunge lock. The principle is simple: A spring-loaded button holds the blade open as it engages a cutout in the blade’s tang. Depressing the button allows the user to close the knife.

Collar Lock

A collar lock or a ring lock is a simple type of lock where a metal collar or ring slides into place and holds the blade secure in the open position. To disengage the lock you simply rotate or unscrew the collar and move it out of position. When doing so, make sure that your fingers are not in the path of the blade. These lock types are mostly used by the Opinel Knife Company out of France on their knife models.

Slip Joints

Slip joint knives have been around for over 400 years and they are probably the most common pocket knife found throughout the world. They work on the principle of a spring keeping the blade under tension at all times. As a result, these types of knives are legal in nearly every jurisdiction in the world.

Some people have the misconception that the blades do not lock, The fact is they do lock under tension but some knives rely on less tension than others and the lock can be easily disengaged under changes in pressure or position. Case Knives and Swiss Army Knives are some of the most common knives of this type.

Friction Folders

A friction folder is a simple knife like an old fashioned straight razor in that the knife has an extended tang. As the knife reaches the open position, the blade is held open by the force and pressure from the user’s grip holding this extended tang inside the handle.

Not as popular in the United States, this type of system is most often used in European countries with bizarre laws against knives that can be locked open. It is as strong as the hand strength of the user.

Lever Lock

A lever lock is a variant of the button lock or plunge lock that utilizes a lever instead of a button. It is not commonly used by American manufacturers but by European automatic knife manufacturers in Europe like Mikov in the Czech Republic.

What is the Best Type of Knife Lock?

All of this begs the question, “Which knife lock is the best?”. That mostly depends upon your needs as a user and for international users or US travelers considering going abroad with a pocketknife.

A frame lock might have the inherent strength of an overbuilt titanium lock bar and hardened stop pin, but it could land you in jail in a foreign country where your only legal option might be a friction folder or a slip joint knife.

Lock back and slip joint knives are often recommended to new users, especially young people because it requires hands to open or close the knife safely.

For everyday use or everyday carry (EDC) some users prefer the Axis lock to the liner lock, but many more seem to use lock back knives as they tend to be cheaper and knives are a working tool after all.

It should be noted that some early liner lock knives were not manufactured correctly because manufacturers tried to evade Walker’s patent and trademarks and did not consult with him on the design. Some of these myths about locks failing persist 30+ years after the fact. However, it is suggested that you use caution when looking at older knives or used custom knives.

Shop Different Types of Knives at BladeOps

This is intended as an overview of various lock types. If you browse through the various samples on the website you can always refer back here to investigate the type of lock on the knife that you are looking at.

BladeOps is your premier blade outlet. We sell automatic knives, butterfly knives, spring assisted knives, OTF knives, and fixed blade knives from the best manufacturers. If our website says an item is in stock, it will ship in one business day.

We retail blades from many different manufacturers, such as Benchmade, Boker, Buck, CRKT, Kershaw, Gerber, Micro Tech, Pro Tech, Smith & Wesson, and many more. We specialize in assisted opening, fixed, and automatic blades from some of the best blade manufacturers in the world. Contact us today if you have any questions about our selection of knives!

This article is reviewed by Trevor Darby, MBA, MBC.

Trevor Darby is a book author and freelance writer as well as owner-operator of a leading knife shop in the United States for the past fifteen years. He has designed several knives and is an authority in the field of specialty knives in the US.

Raised in Hollister, CA, he now lives in South Jordan, UT with his wife and two of their six children. He spends his spare time whittling and writing.