Let’s not mince words here. Some folding knife locks are better than others. And even if you can’t accept that premise, some folding knife locks are stronger than others. 

One of the best of them all, and certainly one of the strongest, is Spyderco’s Compression lock, which was developed by Sal Glesser and which is prominently featured in some of the brand’s top models, like the Spyderco Paramilitary 2. 

Here’s what you should know. 

How It Works (and Why It’s So Strong)

The Compression Lock, commonly billed as a “liner lock at the back of the handle” is in fact much more than that, even though superficially it does look and operate like that. 

In a Compression Lock, there is a ramp at the base of the knife tang that faces upward, rather than rearward, towards the pommel/lanyard end of the knife. This creates a much stronger interface with the lock bar at the top of the knife, near the spine. 

When the knife is opened, the spring tension of a lock bar moves across the tang of the knife, and the bottom edge of the lock bar contacts the ramp, but the key difference here is that the top edge of the same lock bar also contacts the bottom of the top pin.

In a liner lock, only the liner and the bottom of the ramp on the tang of the knife are in contact. If too much pressure is applied downward on the spine of the knife, this gets transferred to the lock bar and the lock can fail. 

In the Compression lock configuration, the lock bar is wedged in place not just against the upward-facing ramp of the tang, but beneath the stop pin, which effectively locks it in place, preventing it from being dislodged. Only an intentional disengagement of the mechanism, or else utter mechanical failure can cause the lock bar to come out of place. 

If force is applied to the spine of the knife, rather than pushing the lock bar off the ramp, it compresses it between the ramp and the stop pin. This is actually where the name of the lock comes from, and makes it extremely strong. Hundreds of pounds of force are required, literally, to force a Compression lock to fail. 

And, on top of the fact that these locks are so reliable and so strong, the fact that the lock bar is disengaged from the top of the knife enables a user to close the blade without putting his or her fingers in the path of the edge. 

Want One? Visit River’s Edge Cutlery 

Interested in adding a Spyderco Paramilitary 2 to your collection? You can learn more about these knives and explore other Spyderco Knives that also have Compression locks over at River’s Edge Cutlery. 

Visit their website and if you have any questions about steel, lock type, or knife design, get in touch with them before you buy. They’ll be happy to assist.

For more information about Spyderco Knives and Hinderer Knives Please visit: River’s Edge Cutlery.