how much should liner lock engage tang?


knife law moderator
Dec 25, 1998
How far over should the liner lock go? I have seen some knives that have the liner all the way to the other side and some that barely contact the tang. Which is right?
This should be a FAQ, for sure.

There's no exact right spot -- by design, the liner changes position with use.

When new, I like to see at the very least the entire liner engaging the back of the blade tang. I like it a bit left of center, so it has plenty of room to wear. If the liner is too far left (partially hanging off the blade), snapping it open or lightly rapping the spine will usually wear it in quick, moving it so it engages to the right more.

I have not noticed that the place where the liner engages the blade is correlated with liner lock failures, provided the entire liner engages the blade. There are plenty of knives that have the liner way to the left, and the locks are very solid. There are plenty of knives whose locks are in the center or to the right, that have auto-disengagement failures.

One nice thing about the liner lock is that it's a self-adjusting mechanism. As the liner lock wears, the liner gets slightly shorter. If you'll notice, the blade tang is cut at a slight angle. That way, as the liner wears and gets shorter, the liner simply moves over to the right slightly, where the tang is angled back further. This keeps the lock free of play through the life of the liner.

When the liner moves all the way to the right, the lock is nearing the end of its life. Once it's all the way right, if it wears just a little more, it will introduce play in the lock-up. Or even worse, on some knives, it will jam between the liner and the blade.

At this point, you can go buy a new knife. Or, if the maker or manufacturer offers this service, you can replace the liner with a new one, or replace the stop-pin sleeve with a slightly larger one. A larger stop-pin sleeve will move the liner to the left again.


[This message has been edited by Joe Talmadge (edited 04 February 1999).]
Interesting post Joe but,I have a question.I have a Spyderco Viele whose liner goes all the way to the right regardless if I snap the blade open or ease it gently open.It`s my sunday going to meeting/dress knife and has seen zero hard use.Do you think the liner was too short from the factory? The blade locks up tight.
I also saw a veile the other day and noticed the same thing. The blade lock-up was solid but the liner was all the way over to the right side, and I mean all the way over. Other than that, the knife was beautiful.

Yeah, if a brand new liner lock starts off way to the right, I do think it came too short from the factory. Hopefully, the lock-up is nice and tight right now. However, once the liner starts wearing, there's nothing else that can happen except for some blade play to be introduced.

In my opinion, when a maker -- I'm talking a hand maker here, not a factory -- makes a liner lock, the liner should just barely engage the blade tang. That way, after a short break-in period (in the initial break-in, the liner usually wears *very* fast) the entire liner will engage the furthest left side of the blade. I believe the maker should do the break-in himself -- he should never be selling a knife where the liner does not fully engage the blade. The maker should hand the customer a knife where the liner fully engage the blade, to the left.

I have learned some things about liner locks from a brilliant folder maker at the Las Vegas Classic show. I'll be posting more in my LV classic review post!

Joe - I had that very experiance with my EDI Genesis, when I got it the only half the liner engaged the tang.

I emialed EDI and got a peak time trans-atlantic phone call from Will Fennel the same day. He said to flick it open hard a few times and after about ten minutes of this, it fully engaged across the tang on the left hand side.

Will said they tried to set up the blades so it engaged at the left hand side of the tang to give you the longest possible life for the knife.

Harvey Wareham

Live Long & Prosper, so you can buy more knives

[This message has been edited by bagman (edited 08 February 1999).]