Heat Treatment Guide

The chart below describes various types of tool steels, their composition and appropriate heat treating applications.

SteelCompositionHarden °FTemper °FAnneal °FNormalize °FQuenchAtmosphere
A2 Medium Alloy 1700-1800 350-1000 1550-1600 0 Air * Air / Inert
A6 High Carbon 1800-1875 400-1000 1600-1650 0 Air * Air / Inert
D2 High Carbon 1800-1875 400-1000 1600-1650 0 Air * Air / Inert
O1 Oil Harden 1450-1500 350-500 1400-1450 1600 Oil * Air / Inert
W1 Water Harden 1400-1550 350-650 1360-1400 1450-1600 Water * Air / Inert
S7 Shock Resisting 1650-1750 400-1200 1500-1550 0 Oil * Air / Inert / Natural Gas
H13 Hot Work Alloy 1825-1875 1000-1200 1550-1650 0 Air / Oil * Air / Endo.
M2 Molybdenum High Speed 2150-2250 1000-1200 1600-1650 0 Air / Oil / Salt * Air / Endo.
T2 Tungsten High Speed 2300-2375 1000-1100 1600-1650 0 Air / Oil / Salt * Air / Endo.
1040 Medium Carbon 1550 1550 1550 1650 Water ----
4130 Alloy Steel 1600 0 1575 1625 Oil ----
4140 Medium Carbon 1575 400-1200 1550 1600 Oil * Air / Dis. Ammonia

Consult with a metallurgist or steel supplier for exact temperature ranges and type of atmosphere for the desired steel finish.