Temper Test

Sando

Sando

Knife Maker
Joined
Jul 4, 2002
Messages
1,148
I'm wondering about testing a blade. A blade that you plan on completing for sale, but before you start on the handle in you want to make sure it's OK. Cutting tests and brass rod are out cause I don't want to sharpen first. I can test HRC, but that's not the whole story.

OK I've heard people do this:

Take a hardened, tempered blade and drop it point first into concrete (also heard mild steel).

Really?

I've tried it from about 12-16" but can't make myself go higher. To my suprise there is no damage on the tip, but can I really go higher? 5 Feet?

Other than that and HRC, is there any other toughness/brittleness tests I can do before I put the handle on? Without sharpening?

Steve
 
Sharpen it up and do some chopping and cutting tests, you can redull it if you want to. I sharpen every knife I make as soon as it comes out of the oven, chop an oak board and cut rope, I want to know my blade isn't to hard or soft before I start the rest of it. Thats just my opinion. Have fun.

Bill
 
I'm with Bill, Mr KnifeMaker Sando. I learned my lesson the embarassing way, finishing a knife that wouldn't take an edge...

Now I sharpen and cut test every blade as soon as I've finished the HT process. Then I dull it for normal finishing.

One thing I wouldn't do is drop it point first onto anything harder than my foot. I figure my knives are at-risk enough just having to survive my handling them, that I'm not going to intentionally abuse them! :eek:

Also I think your hardness tester, so long as you test the edge or hardened area, would be sufficient. Pretty localized though; cutting uses the whole edge. So now I've spouted off, how about you say why you don't want to sharpen?


Looking forward to more opinions,
Dave
 
I have been sharpening all my knives upon completion for edge testing and then take the edge off by running it 'edge straight down' on a piece of 220 grit paper. Then make or send out for making the sheath.

RL
 
Ron Claiborne will get up on a ladder and drop his blades from 6 feet straight into the concrete floor of his shop...I've seen him do it. If your heat treat is dialed in, you shouldn't have any problems...not that I would recommend doing this!

:)

-Darren
 
Yeah Darren, that takes big ones and a lot of confidence. I don't know if I got what it takes to do that one.
 
Dave,

I suppose I don't have a good reason. I s'pose it's 'cause I didn't wanna work with a sharp knife or loose put wear on the edge.

But, if I'm gonna keep grinding the knife after heattreat anyway.....

Steve
 
Right Steve, and just dull it after testing; you're good to work then.

Roger, I know you have the HT processes down to a pretty scientific level and have earned confidence in your methods. But for me I've learned to test my blade immediately after HT, and before I do any more work to the blade - just in case I want to cycle it through again.

Dave
 
Ah, actually Dave - thanks but - that's not at all why I choose to sharpen my knives after completion. It is because I don't like'em sharp when I'm making them. Yeah, I can dull the edge but its still a couple or three mill thick and then there is the buffer too which I fear but use.

If you read the latest HT posts I am involved in you will find for sure I am not so hot at heat treating yet. My latest thing is trying to learn how to look at grain structure. I am making good progress. I see things now but I have absolutely no good idea what I am seeing.

EDIT: I say this purely in jest and in fun only: On one side Steve wants to knock them out six at a time and then you speak to me about recycling them one at a time to make sure they are right. Today I am getting it from both sides. Some I asked for and some came to me.

RL
 
Originally posted by ddavelarsen
I'm with Bill, Mr KnifeMaker Sando. I learned my lesson the embarassing way, finishing a knife that wouldn't take an edge...

Now I sharpen and cut test every blade as soon as I've finished the HT process. Then I dull it for normal finishing.

One thing I wouldn't do is drop it point first onto anything harder than my foot. I figure my knives are at-risk enough just having to survive my handling them, that I'm not going to intentionally abuse them! :eek:
DAVE! i dropped one of my 19" oal bushwacker blades on my foot from about 3 1/2 feet! my strong swedge point percied about 1 1/2" in to the top of my left foot!


:footinmou :footinmou :footinmou :footinmou
Click to expand...
 
Originally posted by RHINOKNIVES
[B:eek:
DAVE! i dropped one of my 19" oal bushwacker blades on my foot from about 3 1/2 feet! my strong swedge point percied about 1 1/2" in to the top of my left foot!
:footinmou :footinmou :footinmou :footinmou [/B]
Click to expand...

Ouch :eek:

when I was doing 440c
I dropped from about 4'feet and this was a finish knife:eek:
it would take a 1/4" divot
out of my cement floor and not hurt the tip
it impressed me:D but still scary:(
 
DAVE! i dropped one of my 19" oal bushwacker blades on my foot from about 3 1/2 feet! my strong swedge point percied about 1 1/2" in to the top of my left foot!
Click to expand...

Laurence!!! Holy Caramba! Man I am lucky, my knives are light - and dull - while I'm working on em. I would not want your Bushwacker headed in my direction ever at all for anything!!! :eek: :eek: :eek: (Well, maybe to be mine! :D )

Dan, anything that will take a divot out of concrete deserves all the pucker you can give it! :D

And Roger purely in the interst of good humor, I don't care what you say; you have confidence in your HT or you wouldn't wait until you've finished a knife to test it. Or you haven't finished one yet and then discovered it wouldn't hold an edge... :D
 
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