Hardening O1 Tool Steel - What Am I Doing Wrong?

One last test. piece is 1/4" x 1/4" x 1 1/2" long.

Exact same results as before but I turned the oven up to 1600 fearing the thermometer might be off at a higher temp.

I thought about the soaking issue. Even at this small though there was no difference.

I think I'm gonna spring for a piece of Starrett O1 and try the exact same procedure and see what I get. That should either rule out my process or the tool steel.
 
The website says TTC Industrial Grade England or USA
 
Not sure if that's a source location or a title; it could after all be used in either England or the USA :grin big:.





A more likely excuse is I missed that and it means it's produced either here or there. Not the first thing I got wrong today. For some reason I got it in my head that TTC was a Chinese import company but apparently I had that wrong. For some reason that actually makes it worse that its's not working.
 
I may be wrong too, but I believe your photo of the wrapper shows the tail end of a word that looks suspiciously like "England".

-frank
 
Frustration does that to a person, been there! :)
 
Here's how frustrated I was yesterday. Every time I pulled the piece of flat bar out to cut off another small slice for a test, I completely ignored the piece of square tool steel that was in the same sleeve with it.

The oven is pre-heating right now. Two different pieces form two different bars. If the results are the same, then the problem is me. It's unlikely that both pieces would be bad (but they did come from the same place so no telling).

New results soon.
 
I agree with Jim Dawson that you might have gotten a piece of mild steel instead of 01. Nothing is impossible. A person had to package that steel,after all. People can make mistakes.

THERE IS nothing wrong with English made tool steel. I have used it for many years.

I have never managed to decarb 01 by overheating it severely,but I would not say it is impossible. But,if it did decarb,it would only leave a soft skin a max. of 1/32" deep at the most. Try filing a corner off more deeply to check.

If you used the same furnace for tempering,was it FULLY COOLED before re setting it to 300º ? I use a toaster oven,pre heated to the tempering temp,and verify that temp by means of a long probed high temperature thermometer I bought from Brownells Gunsmithing Supply. The use of a pre heated toaster oven is from a great little book by Tzumera(sp?) It is sold on Amazon. He is a pro. Of course,I am too. Just retired after 40 years of Master tool and instrument maker in the museum at Williamsburg,Va. I heat treated hundreds of plane irons and other tools,and have been doing so since the 60's.

You need careful control of your temps as there is a 25º "window" in temp. where you'll get the maximum performance from your steel. I AM NOT SAYING THAT THE STEEL WILL NOT HARDEN IF YOU MISS THAT "WINDOW". 01 is pretty easy tool steel to deal with,and I made a large number of 01 and other tools before I had accurate temperature controls. I'm just saying that for the BEST performance,use accurate means of determining hardening and tempering temps..

The best reason to have a PRE HEATED toaster oven ready is that you should temper your steel when it has cooled to where you can BARELY handle it. That is about 140º. Most books will not tell you this detail. Also,if you have drilled holes in your part,STOMP them full of fine steel wool with a flat nosed punch and a hammer. This will keep the hole from causing a crack when you quench the steel,and it will allow the inside of the hole to also harden. Toolmakers used to pack holes with clay,but this had the effect of not allowing the holes to harden. In punch and die work,you need those holes through hardened! So,steel wool is now used.
 
A spark test would be a good idea now. Unfortunately, O1 has a strange spark unlike a simple carbon steel. But, you ought to be able to find a picture somewhere.
 
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