Heat Treat Question ???

teacher

teacher

Joined
Apr 11, 2001
Messages
2,978
Gentlemen, is there a simple method for evaluating / testing the heat treat of a knife without relying solely on the reputation... or lack of........ of the maker ?

Say I buy a knife from a relatively unknown maker ........ how would I really know about the heat treat besides what he has said ?

This is more of a hypothetical question.... I saw it posted in GENERAL KNIFE DISCUSSIONS asked another way slightly ...... but I am curious ??

Seems the answers in that thread are a little more vague... to me anyway. ;)

Is there a method........ ??

Thank you in advance.......... :thumbup:
 
One way would be to find out how or if the maker test his blades. There are simple test like flexing a knifes edge on a brass rod to see if it will chip or deform which would indicate the tempering temperature is either too high or to low, respectively. There are several other test like chopping wood or cutting rope that can be used to test a heat treat.

Another way would be for the buyer to become familiar with the basics of a good heat treat. Study things like the proper temperature for tempering different types of steel that you are interested buying knives made of. If for instance you are buying a knife made of O1 and the maker tells you he tempers the knife at 300F you know that the knife will more than likely be too hard, unless the knife was designed to be that hard. I guess my point is to educate yourself on the different aspects of heat treating so you can ask the maker questions regarding his heat treating methods and recognize when someone is full of it or knows what they are talking about. Finally ask about what type of equipment the maker uses to heat treat their blades. Some one who uses a kiln and proper quenching oils is going to more than likely get more consistent results that someone who uses a forge and transmission oil, although thats not to say that people haven't had success using either of those last methods. Hope this helps.
 
The short answer is no, not a simple way. It would take a fair amount of experience and practice in testing knives.
 
There are two ways to test a knifes HT.
One is destruction testing
The knife is put through a series of tests and ultimately broken.....This is probably not what you want to do.

The other is function testing.
Sharpen the knife, check that it is properly sharpened for the desired use (skinner, fillet, kitchen, camp, etc.) and test it at cutting, slicing,etc. You can do this by cutting wood, cardboard,tomatoes, rope, etc. After some use, check the edge. Is it chipped?, dull?, bent? If it holds up well, then the HT was most likely done right. If it did not, then the HT may have been off, or the steel might be wrong for the function.
Stacy
 
Use, is whats going to give you, the most precise read, on what kind of knife you have bought.
One mans " awesome edge, is another mans, needs some sharpening.


Fred
 
The short answer is no. You are usually safe with products from reputable makers and recommendations from this forum but that is no gaurantee that you won't get a 'Friday afternoon apprentice special'.

If it takes and holds an edge suitable for your tasks then the HT on edge is good. Suitablility for other tasks (batoning/throwing/prying) will depend on how the rest of the knife was treated as well as steel used, shape and construction.
 
bladsmth said:
The other is function testing.
Sharpen the knife, check that it is properly sharpened for the desired use (skinner, fillet, kitchen, camp, etc.) and test it at cutting, slicing,etc. You can do this by cutting wood, cardboard,tomatoes, rope, etc. After some use, check the edge. Is it chipped?, dull?, bent? If it holds up well, then the HT was most likely done right. If it did not, then the HT may have been off, or the steel might be wrong for the function.
Stacy
Click to expand...

That's exactly what I do with each knife after HT. I cut a piece of 8 X 11 cardboard into 1/4" strips and if it'll still shave, I move on. If not, time to re-HT. So in your case, I think a straightforward cutting test might be sufficient. Watching the maker as you start cutting up a piece of cardboard might be illuminating too! :D
 
Pick up the knife in your hand, with a light shining on the blade and examined the blade to see if there any sign of a temper line that was produced in the heat treating process. That is one way. But not all blades will produce a line due to how it was quench. clay coated knife will produce a temper line on the blade and a hard edge softback knife will produce this was well. This is how I produce a temper line. I also like the flexibility in the blade for a straight knife. It reduces the possibility of a blade breaking specially at the tip.:(

You can always check with a file or in some cases use a hardened tester to determined it. But I do not recommend this because you can break the diamond tip and they are not cheap. :yawn:

So, maybe someone else could add to this post and answer the question better. :D

But I will note if its just a scrap knife it does not matter how you test it, if its just for curiosity. :jerkit:
 
I always check my blades with a few center punches, if it flatens the punch, it's hard, if the point penatrates the steel, I screwed up.
 
i have a friend rockwell test my blades anytime i want them tested. so far i have been consistent in getting my blades to the rc hardness that i want. right after i heat treat a blade, i test it with a sharp coarse file along the full length of the edge. if it cuts into the blade, i redo the heat treat. i closely watch the color of my blade before quenching so i dont have this happen very often unless the surrounding light messes with me. if anyone wants to know about my knives, i tell them to ask someone who has one or i let them give one a try and decide for theirself.
 
Thank's for the straight forward answers guys, that gives me something to go on...... :thumbup:

I really am not concerned how the heat treat is achieved as long as it is what it is claimed to be. I know different steels require different treats to achieve a particular desired result.

And that a particular steel can be "given" different toughness and wear resistance charasteristics by slight heat treat variations within a reccommended range.

So......... thanks for the practical "tests" for some simple evaluation. :thumbup:
 
This "question" had / has nothing at all to do with my knife maker friend in Oxford, Alabama ........ :D
......... He knows who he is........ :thumbup: :D ;)... I think he might have been wondering ???? LOL But, I have assured him I never have a question about anything he does..... :thumbup:

...... nor was it about anybody specific at all.

It was just a generic question.... :thumbup:
Thanks again for all the input..... :)
 
You must log in or register to reply here.
Back
Top