Hardening, tempering, annealing and forging of steel; a treatise on the practical treatment and working of high and low grade steel .. . re is a large class of work which can be best heated forhardening in red-hot lead. It is a very rapid and satisfactorymethod for such tools as small counter-bores, reamers, shank,mills, knurls and parts such as bicycle cones, balls, cups, and sew-ing machine and typewriter parts. What makes the lead par-ticularly valuable for heating such parts is that a uniform heatcan be applied without danger of burning or scaling the inside be-fore the center is heated. W
Hardening, tempering, annealing and forging of steel; a treatise on the practical treatment and working of high and low grade steel .. . re is a large class of work which can be best heated forhardening in red-hot lead. It is a very rapid and satisfactorymethod for such tools as small counter-bores, reamers, shank,mills, knurls and parts such as bicycle cones, balls, cups, and sew-ing machine and typewriter parts. What makes the lead par-ticularly valuable for heating such parts is that a uniform heatcan be applied without danger of burning or scaling the inside be-fore the center is heated. When heating in lead a graphite crucible placed so that auniform heat will be maintained beneath and around the pot willprove the best. As to the lead to use, care must be taken to geta brand with as little sulphur in it as possible. Never use scrap THE HARDENING OF STEEL. 107 lead, as it will ruin the steel. Chemically pure lead should alwaysbe used. There are a great many compounds in use to prevent the leadfrom sticking to the work. One of the best is the following: Onepound of powdered cyanide dissolved in one gallon of boiling. FIG. 71.—HEAVY KNURIvS. water; allow to cool, and then dip the articles to be heated in thesolution; remove and allow to dry thoroughly before puttingthem into the lead. Moisture will make the lead fly. Small articles of an even size and thickness throughout canbe put into the lead cold, while irregular pieces must be heated
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Keywords: ., bookcentury1900, bookdecade1900, bookidhardeningtem, bookyear1903
