Heat Treat in the old days
Quote:
Originally Posted by
Bullet Head
I talked to Dave Corbin the other day and he said that his dies are heat treated overnight. Any good ideas for how am I supposed to heat treat my dies? How would they do it in the "old days", charcoal fire perhaps?
Dave means that he gives the die to the heat treater and he gets it back in the morning. I've done this for years, marking the steel type on the die parts with felt pen (also stamped). In modern vacuum furnaces the felt pen marking is still visible after hardening and tempering. In the old days the choice of tool steels was limited; the blacksmith heated the steel until it no longer attracted a magnet (upper critical temperature) at which time the steel was quenched in either oil or brine. After a polish, the die was tempered by color as it was reheated. The color depended upon the use of the tool....light straw is hard and brittle, blue will add toughness. Beyond full blue the color will fade. A chisel would be tempered beyond blue of the striking end and perhaps dark straw on the cutting end. Various compounds are available to prevent scaling when heating in an open fire or a atmospheric furnace. Stainless steel foil wrap is also used to prevent scale.