Type of Steel in Box

mattd

mattd

Joined
Oct 6, 2003
Messages
252
I am trying to get back in to knife making after a six year break. I have some flat stock in a box and am not sure what kind of steel it is. I only remember using 01 and ATS 34 but am not completely certain. The corrosion is consistent on all bars. Some bars have green ends. Is there any way to tell what kind of steel I have?
 
The O-1 has a very distinct spark, dark orange to almost red in color. It will be very straight spark with a few small star burst. I know the paint is used to identify certain steels but I can't remember which is which. The ats-34 will rust before it has been heat treated but that's all I can remember about it.
 
End paint from different distributors is always a crap shoot.
At one job we had 4 different colors for A2. Many of the colors matched other types of steel. White with red stripe was correct. Blue, Green, Yellow were not.
From the Mill Is the real color code. I try to write on each bar every 12" the material it is made out of.
If it is only 2 types, get a known bar of one of the 2 and compare the sparks on a dressed or clean grinding wheel or belt sander.
Sincerely
 
I have zero faith in color codes or chalk marks on any given bar. I only really trust steel that comes wrapped from the mill with their label on it. Why? Grind a knife or two made from "440C" from a popular knifemaking supply retailer, have it HT'ed and come back at 46 Rc (useless), with a note from your HT guy saying "this is 416" and you'll understand. :mad: There were several other blades I made from 440C from a different supplier in the same Ht batch and they came back perfect.

Anyway... I've never used ATS-134 but I've ground up a few feet of CPM-154 which is pretty similar. I've also ground a few feet of O1. Some observations, assuming both are annealed:

O1 will give pretty sparks and lots of them when you grind it. 154, hardly any unless you really lean into it.

Unhardened O1, ground smooth, will blossom orange within 30-60 minutes if left wet. 154 will take longer to show corrosion and it won't be "flash rust", just little pits and spots.

154 heats up slower on the grinder, but when it gets hot it's HOT. O1 heats up quicker but more steadily.

O1 will darken very quickly when soaked in vinegar or lemon juice for a bit. 154 won't.

All these observations are due to stainless alloys like ATS-34 and CPM-154 having more chromium and other elements in them than simpler steels like O1.

Hope this helps!
 
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If you're sure it has to be either O1 or ATS-34 I would H/T a small piece as if it were O1 and if it hardens it should be O1 if it doesn't it should be ATS-34.
 
Do you have some of each?

ATS-34 and O1 grind differently - O1 is soft and ATS34 is harder.
 
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