O1 Tool Steel
|Tempering Temp. º(F):||Hardness Rc|
Punches, dies, trim dies, blanking dies, forming dies, stamping dies, label dies.
Preheat to 1200° F and hold for uniformity. Then raise to 1850° F - 1950° F. Do not forge or roll below 1500° F, cool slowly from the forging or rolling temperature. Do not normalize.
Heat slowly to 1450° F and soak thoroughly. Furnace cool slowly at a rate of 20° F per hour to 900° F, remove and air cool. Expected Brinell hardness 202 max.
Heat to 1475° F and hold 1/2 hour per inch of greatest thickness. Large parts should be preheated at 1200° F and held for uniformity before raising to the hardening temperature. Oil quench 150° F and temper without delay.
Temper before the parts have cooled to below 150° F. Small parts should be held a minimum of 1 hour per inch of greatest thickness and large parts 2 hours per inch of greatest thickness. A single temper is sufficient, but double tempering is a good insurance policy. For most applications a tempering temperature of from 350° F - 450° F is usually specified for the O-1 analysis. 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.