O1 or 154-CM?

[Navin_R_Johnson]

I have a few blades ready for heat treat I cut out and profiled over 10 years ago. I unfortunately can't remember which ones I cut from O1 and which are 154. Any easy way to tell?

Also, any recommendations where I can send the 154 for heat treat?

I'm just spooling back up to start building again after a 10+ year hiatus and figured I'd start by finishing up some of the old scraps I set aside as rejects.

 

[J. Doyle]

You could get some cold blue like birchwood casey's super blue. Or put some yellow mustard on some and see which ones stain real black and which ones don't.

The O1 would turn black with the cold blue or mustard. The 154CM wouldn't.

 

[Self Made Knives]

You must have had them oiled up well, because I can't imagine an O1 blank sitting for 10 years and not showing at least a little patina. On that note, clean them and just drip some water on them. In a day or two it should be obvious which ones are O1.

 

[Navin_R_Johnson]

Thanks guys. I didn't think of an etch test.
I can put a drop of ferric chloride on them tomorrow to see if it sorts things out.

 

[BrandantR]

Thanks guys. I didn't think of an etch test.
I can put a drop of ferric chloride on them tomorrow to see if it sorts things out.

I might be wrong, but I do believe that ferric chloride will etch both types of steel in question. I think you'll be better off using the cold blue or mustard like John suggests.

One more quick idea. If you have a little extra steel to grind away, the O1 will through off a lot more sparks than the 154-CM. It's a pretty noticeable difference.