Heat treat dovetail wedges?

[trinculo]

Just had some new dies made for my utility hammer out of s7.
I need to have some new wedges made and have heard different things regarding heat treating the wedges.

Can someone drop some wisdom on me on weather mild steel is sufficient or should I be looking at something HC like 4140?

thanks,

dw

[pkrankow]

I thought wedges were always mild steel so they could be sacrificed if they get stuck. I would hate to break the bolster or die over a wedge.

Phil

[Rich Hale]

On my lg50 the fit on the dove tails is poor at best. I rely on the mild steel wedges to reshape themselves when driven into place to make sure they fit as well as they can. Methinks a hard steel wedge would not fit itself to the mismatches and loosen up in use more often. But I have not tried a heat treated wedge.

[Sam Salvati]

I have a piece of die key 1/2 the size of a grain of rice imbedded in my gut partly because of a die key because it was heat treated, driving it in with a hammer two hardened and tempered pieces hitting each other is not a good idea. the other part it is there is because the key was allowed to mushroom over and not dressed properly by the previous user.

[Nakedanvil - Grant Sarver]

i can't imagine a mild steel key, but some good reasons have been put forth. Sorry Sam, to me heat treating just means putting it in the condition we want; annealed, normalized or quenched and tempered. Even quenched and tempered can run a huge range, on 4140 anywhere from 55Rc down to 20's. I like my keys about 38 Rockwell. At that hardness they are awesomely tough and hard enough to resist mushrooming. There is nothing quite so brittle as mushroomed/work-hardened steel.

[nonjic]

Mild steel keys tend to gaul (pick up) when driven in, makes them hard to remove. To hard a material and you can deform the dovetails in the ram and tool if the fits not perfect, and of course much to hard and you can end up with a bit of the key in your guts!

I quite like using somthing like en19 't' condition (dont know what this is in american )

[Nakedanvil - Grant Sarver]

"T" is around 300 brinell or 32Rc. My fave is 38Rc which is around 350 brinell.

[forgemaster]

En 19 is 4140, condition T is quench from 850 C deg retemper to about 580 deg C, should come out to about 277 to 311HB (we normally aim for 302HB). Condition T is the standard Quenched and tempered hardness when the machine shops buy already heat treated 4140 bar.

[Patrick Nowak]

The dies keys on my Bradley are made from 4140 left to air cool after forging with no further heat treatment. They are big enough to take a pretty good beating, but they do mushroom and require grinding occasionally. I'm sure they would hold up better if quenched and tempered, but they are adequete for me. If they were smaller keys, then a higher hardness would be important to prevent bending other deformation during driving in and out.

Patrick