View Single Post
  #6  
Old 12-31-2015, 09:08 AM
WNC Goater WNC Goater is offline
Skilled
 
Join Date: Dec 2015
Location: NC Mountains
Posts: 470
Quote:
Originally Posted by jmccustomknives View Post
The nice thing about 1084 is it's forgiving. You should get good results, but you do need to test one. You can take a piece, do this method and break it strait out of the quench. Your looking for a clean break and fine grain structure.
With your blades, out of temper get a brass rod and clamp it in a vice. You'll take the edge and hold it a little steeper than the sharpening angle and press it into the rod. Your looking for the edge to deflect then return. Chipping indicates the blade is too hard, if the edge bends but doesn't return it's too soft.

That and comparative cutting test. Will help tell you how well your blades were done.

Okay, I ended up wading through all 23 pages of the thread you mentioned. (Whew) I see Ray's suggested process for heat treating 1084 etc. Okay, good info. But I have this nagging question that I haven't quite settled. That is, the need to break a blade.

It would seem per your suggestion above, let me rephrase, I don't know what I would learn from breaking a blade out of the quench before the temper. Yes, I could look at grain structure but it seems to me the quality of the blade would be judged at the end of the whole heat treating process which would include the temper. I would expect a blade at the end of the quench to be brittle and bend very little before breaking. Seems after tempering and THEN breaking a blade could tell me something maybe.

But...

If the rod/blade deflection test is successful, i.e. the sharpened edge visibly deflects and returns without bending or chipping, I would think the heat treating was successful. But I suppose it also makes sense that the edge could pass that test but the blade overall be too brittle or soft, but I don't know that to be true. But still, it seems only after the temper process would that be clearly evident. As stated above, I would expect it to be brittle after the quench but before the temper.

So I'm not questioning, just trying to learn, and not quite understanding.

Seems also that 1084, being "forgiving" would be less critical to subject to such stringent testing. I understand different batches can differ slightly with alloys used etc, but by "forgiving" I would think that to mean some temperature variations/fluctuations can be present and still achieve good results.

Perhaps I better understand the break test if using a forge to heat treat (non-temperature controlled) where there are unknown temperatures vs a controlled oven with known temperatures.
Reply With Quote