treblig
There's a range of approximately 500 degrees the can produce true Case Hardening colors, with varying degrees of hardness. True case hardening produces a hard (wear resistant) outer shell, while the core of the steel remains soft. This allows for slight tweaking of the parts if needed.
Now Case Hardening is not a new or novel process, I've got over twenty turn of the century books on the process. Well understood process (at least it was back then). Remember, all sorts of things were case hardened...; car axles, watch gears, even Starrett case hardened their precision measuring tools; it was the quickest way to add a hard surface to soft steel
All types of data: time to temp to thickness of the case ie... 1500 deg for 4 hours will give X thickness of case, or the same can be had at 1600 deg for 2 1/2 hours but you must add an additional enegizer.
And even ways to minimize warpage
V/R
Mike
