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Bath for Hardening Mill Picks
Take 2 gallons rain water, 1 ounce corrosive sublimate, 1 of sal-ammoniac, 1 of saltpetre, 14 pints rock salt. The picks should be heated to a cherry red, and cooled in the bath. The salt gives hardness, and the other ingledients toughness to the steel; and they will not break, if they are left without drawing the temper. 3293. Composition for Tempering Cast-Steel Mill Picks. To 3 gallons of water, add 3 ounces each nitric acid, spirits of hartshorn, sulphate of zinc, sal-ammoniac, and alum; 6 ounces salt, with a double handful of hoof-parings; the steel to be heated a dark cherry red. It must be kept corked tight to prevent evaporation.