H13

H13 is a chromium hot-work tool steel grade in the SAE/AISI H-series, designed for demanding tooling exposed to elevated temperatures. It is highly alloyed, with elements such as chromium, molybdenum and vanadium that provide hardenability, wear resistance, toughness, and good red hardness. The alloy is commonly used for hot-work applications due to its ability to retain hardness and resist deformation at elevated temperatures.

Properties and applications: H13 combines high toughness with excellent thermal shock resistance, making it a standard choice for dies used in plastic injection molding, die casting, extrusion, and forging. It maintains strength at higher temperatures, shows good through-hardening, and offers better resistance to wear and deformation than many lower alloy steels. Typical applications include hot-work dies, extrusion dies, and molds that experience repeated heating and cooling cycles.

Heat treatment and processing: To develop its properties, H13 is usually austenitized at approximately 1000–1050°C (1830–1920°F), then oil- or air-quenched to harden. It is commonly tempered one to three times at about 540–590°C (1000–1100°F) to achieve a final hardness around 50–54 HRC. The material can be machined in its annealed state, but machining is easier with proper tooling. Careful heat treatment and stress relief are important to minimize distortion and cracking during subsequent use.

Variants and related steels: H13 is available in various refinements, including high-purity or vacuum-melted versions with tighter cleanliness. It is often compared with other hot-work steels such as H11, H19, D2, or S7, depending on the specific requirements for toughness, wear resistance, and red hardness. H13 remains a widely used baseline for hot-work tooling due to its balanced properties.