Grade Introduction:

H13 Tool Steel is a versatile chromium-molybdenum hot work steel that is widely used in hot work and cold work tooling applications. The hot hardness (hot strength) of H13 resists thermal fatigue cracking which occurs as a result of cyclic heating and cooling cycles in hot work tooling applications. Because of its excellent combination of high toughness and resistance to thermal fatigue cracking (also known as heat checking) H13 is used for more hot work tooling applications than any other tool steel.

Because of its high toughness and very good stability in heat treatment, H13 is also used in a variety of cold work tooling applications. In these applications, H13 provides better hardenability (through hardening in large section thicknesses) and better wear resistance than common alloy steels such as 4140.

Grade Application:

Hot forging and pressing dies, Extrusion dies, mandrels and punches, Hot chisels, Pressure pads, Extrusion stems, and rams, Blanking and bending tools, Hot heading tools, Backer blocks.

Equivalent grades:

USA Germany Japan
Standard ASTM A681 DIN EN ISO 4957 JIS G4404
Grades H13 1.2344/X40CrMoV5-1 SKD617

Chemical composition:

The following table shows the chemical composition of H-13 steel:

Element C Si Mn P S Cr Mo Ni V Cu
Content (%) 0.32-0.45 0.80-1.20 0.20-0.50 0.03 0.03 4.75-5.50 1.10-1.75 0.3 0.80-1.20 0.25


Hardness tests were made on 1-in. round specimens of H13 which were air quenched from 1850°F and tempered for two hours at various temperatures.

Heat treatment:

H13 tool steels are preheated to 816°C (1500°F). Then the steels are directly heated by increasing the temperature to 1010°C (1850°F) followed by holding for 15 to 40 mins. The steels are then air-quenched.


H13 tool steel is a steel having very high hardenability and should be hardened by cooling in still air. The use of a salt bath or controlled atmosphere furnace is desirable to minimize decarburization, and if not available, pack hardening in spent pitch coke is suggested. The temperature employed is usually 1800°-1850°F, depending on size section.