D7 Tool Steel
|Tempering Temp. º(F):||Hardness Rc|
Brick mold liners, sand slinger liners, dies, machine ways, track packer pads, tile die.
Preheat to 1500° F and soak thoroughly. Then raise to 2050° F - 2125° F. Do not forge or roll below 1800° F, cool slowly from the forging or rolling temperature. Do not normalize.
Heat slowly to 1600° F - 1650° F, and hold for uniformity, furnace cool at a rate of 20° F per hour to 1000° F then air cool. Expect Brinell hardness 235 - 262.
Preheat to 1500° F and soak until uniformly heated and either transfer or raise furnace temperature to 1850° F - 1950° F, and hold 1 hour per inch of greatest thickness. Cool in still air.
Temper immediately after quenching, before part has cooled to below 150° F. Parts should be held a minimum of 2 hours per inch of greatest thickness. Double tempering is recommended. For maximum wear resistance temper at 300° F. The above tempering table may be used as a guide. However, since 1/2" dia. specimens were used for this test, it may be found that heavier sections are several points lower.