WM L6 is an oil hardening chrome nickel tool steel recommended for any tool steel application requiring great toughness, or where intricate shapes preclude the use of water hardening steels it is also recommended for machine parts and other applications having extreme requirements of strength, toughness, and wear resistance.
Heating for forging must be done slowly and uniformly. Soak through at 1800-1900°F, and reheat as often as necessary, stopping work when the temperature drops below 1600°F. After forging cool slowly in lime, mica, dry ashes or furnace. WM L-6 should always be annealed after forging.
Heat slowly to 1400-1450°F, hold until the entire mass is heated through, and cool slowly in the furnace (40°F per hour) to about 1000°F, after which the cooling rate may be increased. Suitable precautions must be taken to prevent excessive carburization or decarburization.
If preheating is not employed, it is good practice to warm the parts on top of the furnace, or in front of the door, before charging into the furnace. The hardening temperature should be 1500-1550°F, depending on the section size.
WM L-6 should be quenched into warm circulating oil. It should be allowed to cool until it has reached a temperature of 125-150°F, or to where it can be held in the bare hand, and tempered immediately.