Tool Steel H13

Tool Steel H13 (AISI H13, DIN 1.2344, JIS SKD61) is the world's most widely used hot-work tool steel, specifically engineered for tooling that operates under extreme thermal cycling conditions. Its chromium-molybdenum-vanadium composition (Cr 5.3%, Mo 1.4%, V 1.0%) delivers exceptional hot hardness — the ability to retain strength and resistance to softening at temperatures up to 600 °C — combined with excellent thermal shock resistance, high toughness, and good wear resistance. These properties make H13 the default material for aluminum and zinc die-casting dies, hot stamping dies, hot extrusion tooling, and hot-runner components in injection molding. It is also the dominant material for forge dies and mandrels in the forging industry. H13 is supplied in the annealed condition and requires heat treatment (austenitizing at 1020–1060 °C, oil quench or accelerated air quench, double tempering at 550–620 °C) to achieve its working hardness of HRC 44–52. Its machinability is excellent in the annealed condition but requires attention to technique when machining hardened material.

Mechanical Properties

• Density: 7.80 g/cm³
• Tensile Strength: 1575 MPa (at HRC 45)
• Yield Strength: 1280 MPa (at HRC 45)
• Elongation at Break: 12%
• Reduction of Area: 35%
• Hardness: HRC 44–52 (heat-treated, working condition)
• Modulus of Elasticity: 210 GPa
• Thermal Conductivity: 28.6 W/m·K
• Melting Point: 1427 °C

Advantages

✔ Exceptional hot hardness — retains HRC 40+ hardness at 600 °C operating temperature; critical for die-casting and hot-forging tooling

✔ Excellent thermal shock resistance — resists cracking under rapid heating and cooling cycles typical of die-casting (10–60 cycles per minute)

✔ High toughness at working hardness — resists catastrophic failure under impact and thermal stress; superior to D2 cold-work tool steel

✔ Good wear resistance — vanadium carbides provide resistance to adhesive and abrasive wear in hot metal flow channels

✔ Versatile heat treatment response — wide austenitizing range (1020–1060°C) allows process optimization for toughness vs. wear resistance balance

✔ Nitriding capability — can be nitrided to further improve surface hardness and wear resistance without additional bulk heat treatment

Machining & Manufacturing

Common Applications