L6 Tool Steel

Chemical Analysis:
Carbon .65/.75
Manganese .25/.80
Phosphorus .030 Max.
Sulfur .030 Max.
Silicon .50 Max.
Chromium .60/1.20
Vanadium -------
Tungsten -------
Molybdenum .50 Max.
Nickel 1.25/2.00
Tempering Temp. º(F): Hardness Rc
As-quenched 65.0
300 62.0
400 61.0
500 58.0
600 56.0
700 53.0
800 50.0
900 48.0
1000 46.0

Uses:

Form rolls, stamping dies, forming dies, shear blades, punches, trimmer dies, pawls, knuckle pins, spindles, clutch pins.

Forging/Rolling:

Heat slowly and uniformly to a temperature of from 2100° F - 2175° F.  Do not forge or roll below 1700° F, cool slowly from the forging or rolling temperature.  Do not normalize.

Annealing:

Heat slowly to 1400° F, and hold for 1 hour per inch of thickness.  Furnace cool at 20° F per hour to 900° F; air cool to room temperature.  Expected Brinell hardness 217 max.

Hardening:

Preheat to 1200° F - 1400° F depending on the section size soak until uniformly heated, and either transfer or raise furnace temperature to 1500° F - 1550° F, and hold 1 hour per inch of greatest thickness.  Quench into 150° F oil.

Tempering:

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.  A single temper is sufficient, but double tempering is a good insurance policy.  For most applications the tempering temperature of 400° F is recommended, but since L-6 does not become brittle like other steels, when tempered in 450° F - 800° F range, it may be tempered at a higher temperature where greater toughness is required.  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.