Is heat treat needed on steel from disc coulters?

[farmboy]

I'm going to carve my first knife out of a flat disc coulter from a 7 bottom plow. The heat won't ever get to be excessive as I work it up, as a lot of my work is with hand tools and a small 1x42 Kalamazoo belt sander.

This steel seems to be pretty tough stuff. Will it be necessary for me to send it off to heat treat before I finish up?

 

[Stacy E. Apelt - Bladesmith]

Yes. While it may be tough, and possible somewhat hardened, it is not hardened and tempered as a knife should be. If you can work it with hand tools (hacksaw, files, and sandpaper) it is not hard enough for a knife as-is.

 

[farmboy]

Yes. While it may be tough, and possible somewhat hardened, it is not hardened and tempered as a knife should be. If you can work it with hand tools (hacksaw, files, and sandpaper) it is not hard enough for a knife as-is.

Fair enough. I’m not exactly sure what it’s made of, but I’m only guessing 1080. I’ll pick out one of the guys here that are in the business of heat treating when I’m ready to go.

 

[Atlas Knife Company]

As I recall, John Deere discs are 1075'ish. You'll be money ahead to anneal, shape, then HT. Trying to work them as-is will surely ruin the temper and take a LOT more grinding than annealed.

 

[farmboy]

I think I can handle that. I remember many, many years ago I was working on a hydraulic jack or piston, or something like that. I can't remember, really, other than we were working on the combine, and I was having a helluva hard time drilling a hole. I was down to my last bit, and didn't want to break it or some damned thing...........

At any rate, I can stack up some fire brick and see what I can do. Thanks for the tip, at any rate. I might save a little money on belts if I soften things up a little.

 

[Natlek]

As I recall, John Deere discs are 1075'ish. You'll be money ahead to anneal, shape, then HT. Trying to work them as-is will surely ruin the temper and take a LOT more grinding than annealed.

Many knife maker grind bevel AFTER HT so they ruin the temper ? Even when blade is HT with already grind bevel/ oversize/ we grind post HT to to get proper dimension on edge ? And that is most dangerous part of grinding , because blade is very thin on edge ? Speed , good belt , cautiously , bucket with water and no problemo .I just grind this blade from 7mm thick file ...........edge is almost sharp I guarantee You that the temperature did not reach up to 60 degrees Celsius .