When is a knife worn out??

Feb 18, 1999
Giving credit where it is due, this thread is inspired by a post from Madpoet in the KF.

I have heard of BM Strykers after only a couple years or so being worn out from use. I've seen a BM Tsunami (belonging to a cop friend of mine) with slight blade play in all directions but otherwise going strong after years of almost daily use. Seen a CQC-7 approaching worn.

On the other hand, I've both owned and heard of others owning/using more traditional lockback and slipjoint folders for decades before wearing out...sometimes even still going strong after regular use.

Of course, any knife can and will wear out with enough use. But it just seems by observation that so many of the new, more expensive, high-tech one-handers may not have the longevity of the older-style knives.

I suppose only time will tell as to durability for daily use/carry for such knives as linerlocks and axis/rolling-type locks. No one has yet carried such knives for decades.

Perhaps it is extra-hard use/abuse the newer knives are being put to? Has anyone else made these observations?
I've had lockbacks get sloppy on me, but I've never had a quality(read "Buck") lockback give on me. I work them harder than most work their fixed blades. Up to and including chopping apart 1.5 inch thick branches for firebuilding. Before I realized it was real dumb, I used to practice full-strength thrusts against living trees with my Buck lockbacks. They never gave out.

I have never seen a linerlock that I would carry. Don't try to convert me. It won't work. I have seen/held just about everything out there. I know materials and construction. The best I've seen are only equal to a lockback, not better. Newer, more exotic locks I can't speak for.

Linerlocks require a skinny, floppy strip of titanium or steel to hold the knife open. All springs lose their springiness with use. The problem is, linerlocks stay locked by the virtue of their springiness alone. Lockbacks only rely on it indirectly. A strong spring helps, but as long as a lockback's lock is engaging the slot in the blade, the stresses are on the thick lock and pins, not the spring directly.

There is room for improvement in lockback design. Next year hopefuly, I'll be able to start bladesmithing again, and one of the first things I'm going to make is an improved version of my Buck Titanium. I'm radiusing the hard angles of the lockwork, making it more like a single-toothed ratchet, and using a coil spring. Initial experiments are very promising. I also am working on an improved version of the classic clasp-lock.

As to when a knife is worn out, for me it's when the lockwork is too loose, blade too chipped or scratched, crossgaurd too loose, when it's too rusted or lost so much metal from resharpening that it can no longer take a satisfactory edge. The last only happened to me when I was still using carbondum stones.

[This message has been edited by Snickersnee (edited 14 June 1999).]
A knife is worn out, when YOU thinks it's worn out. What matters is that you are happy with it and it serves you well.
Ofcourse when it's falling apart I would think of renewing it:-

Steen Hansen

Never, thats what a life time warranty is for !!!!

All of God's Critters may have knives, but most of them are stamped with the name BENCHMADE
I still have an use knives that were my fathers and grandfathers, as well as my own. But yes, knives do wear out, when there is no more useful size left to the blade from sharpening for they finally get to the point where they are soooooo loose they start to fall apart.

Depends a lot on how you use them. Also with the new materials being used I would think that current knives will last longer than my grandfathers (One of which was made in the 1890's)
This is an interesting question that I fear only has a subjective answer. My personal thinking leans toward a knife's being "worn out" when it no longer functions properly. Be it a blade that will no longer take an edge effectively, tolerances that are loosened over time that affect parts which cannot be replaced (don't forget--a liner lock as well as other types of locks and springs can be replaced), or you break a part which cannot be replaced to original tolerances.

seems to me....that given the ease of taking the new style of folders apart and reassembly, that any knife can be made into like new condition fairly easily.....seems to me.....just do it....
Most knife owners think that a knife is worn out becouse it won't hold and edge anylonger.
In truth it is usually due to the fact that the cutting edge has been sharpened away to the point that the edge is too thick and creates too sharp of and angle (V) on the shoulder. It is is impossible to put an edge on a blade like this and get it to stay. The only remedy (sp) is to thin the shoulder to create a good geometric edge. It will amaze you how the knife comes back to life.

If the blade is shorter than 1/8 of an inch it's probably time to get another knife or replace the blade.

goshawk http://www.imt.net/~goshawk

[This message has been edited by goshawk (edited 23 June 1999).]