What Is A Lock Knife Used For?

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If you found yourself here, that probably means you’ve been reading up on the different types of knives and their uses.

And I don’t need to be the one to tell you that there a whole lot of different types out there.

But if you’ve been looking around for the right pocketknife for you, then chances are you’ve probably stumbled across the term lock knife more than once.

This is one of the most important designs for knives out there, but what exactly is it?

In this article, we answer the question, “what is a lock knife?”, and even dive into the different types out there and whether or not you can own one.

So read on to learn more.

What Is A Lock Knife?

Basically, a lock knife is a pocketknife equipped with a foldable blade that can fit inside the handle. This will allow you to safely put the blade in your pocket and go around your business and only exposing the sharp edge and pointy tip when you need to.

Aside from being compact and easy to carry, this can be a very safe tool to have at your disposal and it has a bunch of different uses.

Depending on the type of blade you get, you can use it to either cut through different materials like rope, slice through meat, and just about any outdoor and survival task you can think of.

That being said, there are a lot of different mechanisms that are used to keep the blades inside the handle, and we’ll go over the most popular ones in the next section.

Types Of Knife Locking Mechanisms

Slip Joint

The slip joint, along with the friction folder, is the precursor to knife-locking mechanisms.

You see, folding knives have been around for a long time, and they can be traced back as far as the Roman Empire, but true locking blades have only been around for a little bit more than a hundred years.

The slip joint came around in the 1600s in England and is the closest thing you can come to a locking pocketknife before modern mechanisms were invented.

The mechanism uses spring pressure to keep the blades folded and safely inside the handle and can be commonly seen in Swiss Army and old-school hunting knives.

To open these blades, you need one hand to pull the blade out and “slip” it into place to lock it in, and another hand to hold the handle firmly.

And to fold it back, simply apply pressure to the spine of the blade until it folds back in.

Ring Lock

This is another popular mechanism that was invented in 1955 by Maurcel Opinel.

It’s an improvement on their old folding blades that are riveted into the handle by using a shell ring.

Opinel took the idea of the shell ring and tweaked it so that it rotates over the handle when it is open, locking the blade in place.

The ring rotates over the handle when opened, which is what holds and locks the blade in place, and in the 90s, the technology was further improved upon, allowing the ring to be locked even when the knife is closed, allowing you to keep your blade safe in your pocket.

Back Lock

Also called the lockback or spinelock, this system is an improvement on the old-school slip joint system.

It generally follows the same principle of the slip joint, but the difference is that there’s an interlocking spine system, which serves as an added safety measure.

So that means that when the knife is open, it will not accidentally slip back into the handle.

To close the knife, you will have to move an exposed section of the interlocking spine which unlocks it and allows you to fold it back in.

Liner Lock

This is one of the most common and reliable mechanisms on the market and is used by a whole lot of different knifemakers.

It has a spring-loaded metal liner inside the system that remains under pressure when it’s closed and also keeps the blade in place when the knife is closed, keeping this locked and safe.

However, when the knife is opened the liner pops up and wedges the blade, locking it in place.

To close it, all you have to do is press the liner away from the blade while folding it in.

Is It Legal To Own One?

Like most knives and survival tools, the legality varies depending on where you live.

These blades aren’t as regulated as other knives, however, just to be safe, make sure to thoroughly check the rules and regulations that your locality has when it comes to wielding blades.

That way, you’ll be sure that you can own and carry one of these knives for yourself.


And with that, our article comes to an end.

Now that you have all this information on lock knives, the only thing left to do is figure out if you need one in your life.

And if you do, well, the next step after that is finding out if you can own one in your state or country, and then heading out and getting one yourself!

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My name is David Strong. I'm a knife expert and a US Marine veteran. I used to fight in Iraq, so I gained lots of combat experience there, especially when it comes to combat, tactical, and outdoor knives. And this blog is where I share my expertise with you alongside my friend Andy.