Heat Treat 0-1 via Flame to high 40's for a Thrower?

[P.Brewster]

I know next to nothing about heat treating, so I need some advise please.

I make shuriken (Japanese throwing spikes) out of square stock. I usually use cold rolled (which obviously is not heat treated).

A customer wants some made from tool/high-carbon steel.

O-1 is what I found locally, so that is what I'm working with.

I'm wondering if there is a low-tech way for me to get my spikes up to a hardness that's appropriate for a thrower. If I am not mistaken, I believe I am aiming for about 48 (Rockwell C) to get a tough tip.

I have access to torches, but no oven.

Any guidance would be greatly appreciated.

 

[AcridSaint]

You'll want to read about general heat treating and then heat treating O-1 in particular. I don't believe that a torch gets the "most" out of O-1, but it doesn't seem like that's your intent.

Looks like you'll need to get it up over 800* if you want it to be under 50RC

www.engnath.com has a lot of good, readable info on knifemaking and steels. You can google search blade forums if you want to look up info here.

 

[Nathan the Machinist]

There are tougher tool steels than O1 at HRC 48. I think MSC sells S7 or perhaps you could find some L6?

Regardless, it will work and is easy to HT. You can heat with a torch and quench in vegetable oil for a real basic O1 heat treat. Not the best, but workable.

You'll want to read up on what the glow at 1500 looks like (your aim hardening temp) and what color oxide film will be present at your tempering aim temp.

 

[P.Brewster]

Thanks gentlemen.

Nathan, you mentioned S7. From what I've read, it sounds ideal for a thrower.

Does anyone know how it would hold an edge? Would it be good for a chopper?