Hey guys I have a question to pick your brains with. I have been outsourcing my HT, and seem to be getting good performance, but the blades seem to be warping more than they should. I don't mean a end to end warp, but a fried bacon edge. I try to leave the edges at about .030 before heat treat and maybe thicker by a hair. The last few I sent were a bit lower and mic'd out at about .020 - .025 at the edge. The guy called me and said that they have edge warp and I may have to grind them out and change the profile to salvage them. I was told by him to leave the edge at .040 at the very least, and thicker if I could. This seems a bit excessive and I am wondering if maybe the blades are being overheated or if its from pressure in the kiln rack. I don't have any pics of this right now, but I should add that they blades are all 1084 or 5160. The blades I had done by him in CPM154 were .030 at the max and came back arrow straight. Any thought on this?
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Edge thickness, edge warp, and possible overheating.
- Thread starter Grayzer86
- Start date
Fred.Rowe
Knifemaker / Craftsman / Service Provider
- Joined
- May 2, 2004
- Messages
- 6,848
I think you can take the 154 thinner for heat treat than the 1084. The request for .040 seems correct for 1084. The fried bacon edge is a good indicator that the edge was too thin when quenched.
If you are sending the blades to someone with the proper equipment I would not think the steel is being overheated. They could ruin their business with reports like that. Personally I leave .035 to .045 for heat treat and I'm doing my own.
They should be running the 1084 at 1550 to 1600 for hardening.
Hope you get that worked out.
Fred
If you are sending the blades to someone with the proper equipment I would not think the steel is being overheated. They could ruin their business with reports like that. Personally I leave .035 to .045 for heat treat and I'm doing my own.
They should be running the 1084 at 1550 to 1600 for hardening.
Hope you get that worked out.
Fred
Thanks for the info Fred. The current batch I am working on have all been left at .040 or a bit thicker so I will see how this turns out for me. I didn't want to point fingers saying that he was overheating but thought I would ask here and see if my edge thickness was correct. I will see how bad these last ones are when they get back as I don't know for sure what his definition of edge warp is as far as severity goes. I had no intention of causing him a problem, so that's why I made sure to leave out any info that would lead to his name. He is not a member of this forum. On a final note I could not believe how clean that CPM154 came back. I actually thought maybe he missed heat treating it until I saw the dimples and hardness reading written on it. It was the first stainless I had ever had done
Might be a stupid question but how long are the blades? Most of my knives are 1084 with somewhere between 3-6 inch blades and I don't get any edge warp if i take them to 0.025-0.035". BUT i just did a 10" bowie blade and left the edge at 0.040" and it had the "fried bacon" edge. It could not be saved. Plan "B" is ground right now, awaiting heat treat and I left it at 0.080".
randy
randy