Knife testing...what am I looking for?

[silver_pilate]

This question has been bouncing around in my head for a while now.

We've all read the knife destruction tests where the knife held up great through chopping multiple branches, 2x4's, rope, etc. and shows no edge damage and is still able to shave hair. The brief of the description is that the edge comes through in the same shape it started in.

My question is, how much edge wear/damage is acceptable? I've taken some of my knives out and chopped through oak 1x4's and branches, sunk the edge in and forced it out by prying the knife sideways, etc. After the wooden destruction, there was no chipping or folding of the cutting edge, but obviously keenness is reduced. You can visibly see the wear/scuffing on the formerly polished cutting edge. I can still shave hair from my arm, but it's more like scraping the hair off as opposed to popping hairs off crisply.

I guess I've got this fantasy idea in my head of a knife that can handle all kinds of cutting/chopping tasks and still pop hairs off the arm as good as before the testing and shave up tissue paper like it's nothing. Is that the standard I'm shooting for? I can't see any knife being able to live up to that standard. The things we use knives for, whether it's shaving arms or cutting down saplings, will dull a knife. I can't see any other way around it.

What do you guys look for in your own knife testing? How much wear is acceptable? I once spent about 30 minutes slicing up junk mail and credit card offers that had stacked up on the kitchen table. The knife still cut well at the end of the session and even scraped hairs off, but it was hardly comfortably shaving sharp. Give me some ideas of what I'm looking for.

Thanks!

--nathan

 

[Onies]

Hi Nathan,

I am very new to this hobby, only made about 20 knives so far. As far as the testing goes, I tend to do a side by side comparison with one of the many production knives I own. My goal is to create something that can surpass a knife purchased from a store in a head to head competion. I have only used 01 tool steel so far, so testing against 440C, ATS 34 and AUS 8, and 1095 may not be fair, but I can confidently say my knives will stand up to as much or more use/abuse than any production knife I have tested against. Where my blades really shine is when one of my hunting buddies brings along a flea market special. Invariably they ask me to hand over one of mine to finish dressing or skinning a deer. I've actually managed to recover my cost on a couple this way.


Fred

 

[silver_pilate]

I'll have to take out one of my comercial campers and try it out against one I've made.

Don't get me wrong, I don't want to sell anyone something that I'm not fully confident in, and I have tested enough of my knives to know that they will hold up pretty well. However, I'm just searching for that standard so that I know my knives really do stack up against some of the other custom makers out there.

I also know that you heat treat your knife to a given purpose. I'm not interested in finding a use-for-everything knife; I just want to make sure that there are no flaws in mine. If they can survive X, Y, and Z without failure, then I'll know I did my job pretty well for a general use knife.

I'm just interested in how you guys judge yourself when you test a knife to destruction. What kind of standard to you try to uphold.

Thanks!

--nathan

 

[silver_pilate]

One time TTT.

 

[Will Leavitt]

Here's my testing regime for a new heat treat process/steel. I'm mainly looking to verify it against MY known standards.

I have a 4" hunter that I keep in the shop as a benchmark knife. All cuts are compared to that knife, it's sharpened the same way every time.

I cut 1/2" sisal rope, I cut standard cardboard, I whittle on YP 2x4s. This tests edge retention. I expect a knife to make X number of cuts, you can tell a lot about an edge from the type of "curl" and the thinness of the piece cut from pine. Thin and curly is very good, thick chunks aren't.

For larger blades chopping 2x4s and stuff ensure the blade is up to impact, I also will smack the spine and flats against an anvil to test this on blades not up to chopper size.

I will hammer the blade through a nail, this test is for my satisfaction. I'm looking for impat resistance here, I do expect the edge to deform but don't want to see cracking. This test simulates a hard strike or when you're hammering the knife through a log while camping.

Then I'll break the blade into pieces to look at the grain structure.