die case hardening depth

[roysha]

Can anyone tell me how deep the case hardening is on sizer dies? Does the hardness vary with the depth?

[EDG]

I have cut up several RCBS sizers. The case seems to be only about .008 to .010 deep.
The surface is probably about 64 Rockwell but the core is easily machined or filed.

As far as variations in hardness with depth - the case is so thin that a Rockwell C penetrator punches through the case.
That is the penetrator is a conical diamond. When the preload is applied the pressure on the diamond is so great that it actually pushes into the soft metal behind the case. To correctly test the surface you need a superficial tester and I have never had access to one of those.

[str8wal]

In a kind of related topic. Would the seater dies be of similar construction? I want to drill out an RCBS seater die that has a 1/4" seater plug and tap it for a 1/2" plug. Would this be feasible?

[EDG]

You need a nice quality smooth cut file - maybe a 10". See if it will cut the top edge of the die.
If it will cut the die you can machine it. If it does not cut it it is too hard unless you have carbide tooling and a lathe.
You can anneal the die by putting it upside down on a natural gas flame until it turns deep blue. Slowly reduce the flame over about 30 minutes and then turn it out. Let the die cool in air without moving it.
It should be easily filed. Then do the machine work in a lathe to keep you new plug on the centerline.


In a kind of related topic. Would the seater dies be of similar construction? I want to drill out an RCBS seater die that has a 1/4" seater plug and tap it for a 1/2" plug. Would this be feasible?

[str8wal]

Thanks for the info!