While at the local steel supplier, the manager gave me a 3/8 x 1 x 36 piece of O-1. What would be the best use of this size and type of steel? I'm thinking that it would be hard to reforge to round or square without the risk of cold shunts, even with a power hammer. I have no experience with O-1 but knew that I wasn't going to say 'No' when it was offered LOL Thx, Keith

I use O-1 at work,and do some torch hardening on some parts. It will get brittle hard if taken to a red heat. To just toughen it, I will do a dulllllll red, and quench, or air cool if the part is small.

O-1 makes some good knives, but I wouldn't think to use it for any tools to be hammered on.

Annealing, and tempering take a controllable oven to do right.

O-1 isn'tthat expensive, but you may be able to trade it for something else better suited for what you want to make.

O-1 is an oil hardening steel suggested for use in dies, punches etc, I googled it but did not cut and paste that on here as that may need approval from the site I read. I have used alot of it for knife blades. I grind not forge to shape but have hot forged some in the past. A wee harder than mild under a hammer. I go right by the book on hardening and tempering for my blades. They hold a wonderful edge. Most knife supply houses carry it as well as places that provide for machine shops etc.

Annealing, and tempering take a controllable oven to do right.

I disagree, While one needs to take care as O-1 can air harden, annealing isnt to hard in a box of vermiculite, and tempering is simple, how do you figure the need high tech controls for tempering?

I have seen rams heads forged into the handles on small knives with O-1 just gets tricky with heat but its not too bad.

I disagree, While one needs to take care as O-1 can air harden, annealing isnt to hard in a box of vermiculite, and tempering is simple, how do you figure the need high tech controls for tempering?

Not high tech, but controlled temp. I have tried annealing some parts at work, but when they were removed they were still too hard to deal with. A lot of what I work with is small sections, and they tend to stay hard. To get them soft enough to work without chipping I needed to keep heating them with a torch for quite awhile to extend the cooling time. We have an oven running now, so it won't be a problem in the future. Tempering was also a problem without an oven, as they air cool so fast. I tried running colors, but that wasn't even near close enough to what we needed.

Sounds like a lovely piece of big knives where you want to forge it out wider and thinner.

Cut it in two lengthwise and you have a good piece for smaller blades.

I'd definitely think about blades with it as it's a good alloy for that!

can someone give me a link for annealing and tempering o-1 for knife blades. thanks.

can someone give me a link for annealing and tempering o-1 for knife blades. thanks.

You may want to start in our Knife making section, in the heat treat for ideas. http://www.iforgeiron.com/forum/69-heat-treating-knives-blades-etc/ the main thing to remember is O-1 likes to air harden in blades, so working in O-1 never lay on the anvil to cool.

Especially in COLD weather---watch out for the postvise too!

thanks for the help, I do have a can of vermiculite, and am trying to get the tempering oven working. thanks again.

O1 has ~1% carbon and plenty of carbide formers like chromium, tungsten, and sometimes vanadium. Traditional slow-cool annealing from above critical in something like vermiculte or wood ash is likely to get you grain boundary carbides that can make it very hard to drill, even after "annealing," and which are likely to remain -- causing unnecessary brittleness -- after hardening and tempering. (If you look at industrial recommendations for annealing O1, it's a sub-critical spheroidizing process.) O1 also needs a proper soak to get all the carbon into solution before quenching, because the alloying elements get in the way. I have made knives from O1, and they certainly got hard when heat treated with simple methods. They were also very difficult to sharpen, even after tempering. (Knowing what I now know, I suspect that was because there were big, nasty, extremely wear-resistant carbides in the matrix.) I have since learned enough to realize that the microstructures of those blades probably are far from ideal. I second BGD's comment that O1 is a steel that should be heat treated with proper equipment in order to get close to its potential. I have quite a bit of O1 stock that I will not touch again, at least for knife blades, without a proper, temperature-controlled heat treating furnace.

thanks i see you point, I don'[t have a lot I think I bought a couple of rods to try it out. I think I also bought a couple of a-2 i think.