Originally Posted by SidecarFlip
I must comment that dimensional stability as it pertains to commercial heat treatment is entirely in the hands of the heat treater and their competence level. No supplier will guarantee dimensional stability that I know of, however the people I deal with come through consistently with very littel dimensional change.
There will always be a bit, after all you are realigning the structure and it will move.
good point! There is virtually no steel that dosn't change under heat. Some more than others. I've even seen 4xxx series steels change all over the place in a nitirde process. Looking in the Carpenter manual, they do spec the change outs, but I think that's a lot of guess work.
For a heat treat some to get my buisiness, they must be of aircraft quality first. Then I look to see if they can do the exotics, as this gives me an idea what they can and cannot do. I'm lucky as I have two in my area. One is a small shop about ten minutes north of me, but if it's gotta be seriously right I goto one up in Indy. I probably didn't use either one a dozen times as I had access to a state of the art heat treat facility. But I liked the way the one in Indy did air hardening processes best.
You are probably a light year more upto date on steels than I am for the most part. I may have delt with some of crazier exotics but you still ahead of the game here. I honestly think the operator doing the draw process is more imortant than the guy doing the initial heat treating and quench processes (also can be extremely critical). I've had a few jobs trashed by the quench tank alone! The best thing I ever did was to order in a good agitating system to seriously circulate the quench oil. Then I brought in Castrol and a couple others to try different oils. I settled on Castrol by the way.