H13 Steel Hardness

The hardness of H13 steel depends on its condition and heat treatment. Supplied H13 is normally annealed for machining, usually around 220–241 HB. After quenching, standard sections may reach about 51–54 HRC, while large sections can show lower core hardness.

After tempering, finished H13 tools are commonly adjusted within about 38–55 HRC. Many hot-work tools work around 40–48 HRC, with lower hardness often used for heavy shock and higher hardness used where wear resistance is more important.

Final hardness can change with section size, austenitizing temperature, cooling rate, tempering practice, and test position. For most H13 tooling, the target is balanced hardness, not maximum hardness.

Aobo Steel supplies H13 tool steel in an annealed condition for bulk orders, including round bar, flat bar, plate, and forged block. For purchase, see the H13 product page or contact [email protected]

H13 Tempering Temperature and Hardness Chart

Tempering adjusts quenched H13 to its final usable hardness. It reduces brittleness, relieves internal stress, stabilizes the microstructure, and improves service reliability.

H13 is commonly austenitized at about 995–1025°C (1825–1875°F) before quenching. After quenching, it is usually double-tempered or triple-tempered to improve stability and reduce the risk of brittle failure.

Some values overlap because different reference data may use different austenitizing temperatures, quenching methods, holding times, section sizes, and test positions. These values should be used as H13 heat-treatment guidance.

For hot-work tooling, the highest HRC value is not always the best target. A slightly lower but more stable hardness can often give better tool life when the tool faces impact, thermal cycling, or large-section stress.

Recommended H13 Working Hardness by Application

The optimal hardness for H13 depends on how the tool operates and how it is likely to fail. Die casting, forging, extrusion, and high-shock tooling place different demands on the steel.

For die casting dies, hardness must be balanced against heat checking. Large inserts are often kept at a lower hardness to reduce the risk of cracking, while smaller inserts can be made harder when wear resistance is more important.

For forging dies, impact severity is the main concern. Hammer forging normally requires lower hardness than press forging because the loading is more sudden and severe. If hardness is pushed too high, the die may crack before wear becomes the main problem.

For extrusion tooling, the tool function matters. Dies, mandrels, dummy blocks, rams, liners, and containers should not automatically be assigned the same hardness, as they experience different thermal and mechanical loads.

A simple selection rule is when wear and plastic deformation dominate; a higher working hardness may help. When cracking, chipping, severe impact, or thermal fatigue dominate, a lower or more balanced hardness is usually safer.

For bulk H13 tool steel supply, Aobo Steel can provide annealed round bar, flat bar, plate, and forged block, with inspection documentation, as per order requirements. For purchasing support, please contact [email protected].