As part of my job, I sometimes require special tool that I don't have. It would be great to make them myself, and more importantly harden and temper them to tool steel quality. Anyone have a suggestion as to the procedures to achieve this using oil quenching?
Actually I wouldn't recommend an oil quenching process unless you can create a pretty hot forge or furnace ... dangerous stuff for garage work. Instead consider the use of A2 tool steel which is "air hardenable". See the following link: http://www.practicalmachinist.com/vb/general-archive/procedure-hardening-a2-79003/
Oil-quenching is only used as the last stage of manufacturing of 'hardened steel' tools, and give a darkened look to the surface finish. The carbon atoms in the oil molecules going into the surface interstitial spaces is what does the hardening.
I agree with Mark The Oil Hardenable alloys are a poor choice if precision is required the tool may warp and thus require finish machining after hardening to account for movement. If you can afford A2 or 440C to name two of many these have well defined heat treatment spec's that are air cooled . Ideally you have a small shop electric furnace to insert the tool into. Also research if the alloy has an oxidation temperature that is below the heat cycle if so it may require an inert atmosphere to keep from heavy scaling. You did not mention how special the tools are you sometimes require are they wood working chisels etc in which an old file could suffice ground to a sharp shape and then reheated to bring back the temper lost in grinding. Or are these machined parts? Dave
