Does anyone know what type of steel The Perfessor used to make his sizing dies?

[Reverend Al]

Does anyone happen to know what type of steel "The Perfessor" used to make his Lyman / RCBS lubricator sizer die blanks from? I have 6 of his blank dies that have 3/16" pilot holes pre-drilled that I bought from him several years ago and we need to know what type of steel he used so that we know how to go about hardening them after they are bored out to the custom sizer die diameters that I need. If anyone has any information on what steel he might have used I would very much like to hear from you!

https://i.imgur.com/uOgx5tS.jpg

[EDG]

Have you checked the existing hardness of them?
If they were about 32 Rockwell they might have been made of prehardened 4140 and don't really need heat treat. At least that is what I would use.
You might use a few of them without hardening for a couple of years and decide they do not need hardening regardless of the current heat treat.

[Catshooter]

IIRC he used 12L14 which is a leaded steel, so not hardenable.


Cat

[Reverend Al]

Thanks for the info, much appreciated. I went and had a look and here is what he said.

We use 1144 steel, which is a free machining resulphurized steel with approximately .44% carbon content. It machines beautifully and can be polished to take on a great surface finish. It can be quench hardened if desired but for sizing lead alloy bullets it isn't really necessary. If your alloy is clean (no gritty particles trapped in it from inadequate fluxing and cleaning) you can expect very little wear for hundreds of thousands of rounds.

[beagle]

We made some locally and hardened steel was not used. This was several years back and so far no wear has been detected. This was with 4140. RCBS surface hardens theirs./beagle

[Alstep]

I've made some dies and expander plugs (like the "M" die) with what our steel supplier calls "stress proof" steel bar stock. It's pretty hard stuff, but machines nicely. Seems to hold up well without heat treatment.