AISI H13 Hot Work Tool Steel: Die Casting, Extrusion & Forging Die Properties
ASTM A681 / NADCA #207 / DIN 1.2344 · Published: 2026-05-31 · Updated: 2026-05-31
AISI H13 is the most widely used hot-work tool steel globally — the workhorse material for aluminum die casting dies, extrusion tooling, forging dies, and mandrels. H13 is a 5% chromium hot-work steel (0.35-0.45% C, 4.75-5.50% Cr, 1.10-1.75% Mo,...
AISI H13 is the most widely used hot-work tool steel globally — the workhorse material for aluminum die casting dies, extrusion tooling, forging dies, and mandrels. H13 is a 5% chromium hot-work steel (0.35-0.45% C, 4.75-5.50% Cr, 1.10-1.75% Mo, 0.80-1.20% V) that maintains approximately 45 HRC hardness at die surface temperatures up to 540°C (1000°F). Its key attribute is resistance to heat-checking (thermal fatigue cracking from repeated heating-cooling cycles) — the primary failure mode in die casting and extrusion tooling. Premium H13 grades (VAR/ESR remelted, premium H13 per NADCA #207) with controlled sulfur (<0.003%) and minimized micro-banding provide up to 2-3× the die life of commodity H13 in demanding aluminum die casting applications.
Quick Facts
| Category | Tool Steel |
| Standard | ASTM A681 / NADCA #207 / DIN 1.2344 |
| Density | 7.76 g/cm³ |
| Yield Strength | 1100-1600 MPa (160-232 ksi) depending on tempering temperature |
| Tensile Strength | 1200-1800 MPa (174-261 ksi) depending on tempering temperature |
Global Equivalents & Cross-Reference
| Alternative Standard / Grade | Action |
|---|---|
| EN X40CrMoV5-1 | Compare |
| DIN 1.2344 | Compare |
| JIS SKD61 | Compare |
| GB 4Cr5MoSiV1 | Compare |
| Böhler W302 | Compare |
Related Materials
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Calculate the weight based on this material's density: 7.76 g/cm³
Frequently Asked Questions
What is the optimal heat treatment for H13 die casting dies?
Per NADCA #207: Austenitize at 1020-1040°C (1870-1900°F), soak for 20-30 minutes at temperature (not including ramp time), quench in vacuum/pressurized gas or warm oil to below 70°C (160°F) before tempering. Triple tempering is essential: Temper #1: 540-560°C (1000-1040°F) — transforms retained austenite to martensite; Temper #2: 560-595°C (1040-1100°F) — tempers the fresh martensite from Temper #1; Temper #3: 540-580°C (1000-1075°F) — ensures complete transformation and dimensional stability. Target hardness 44-48 HRC for aluminum die casting. Skipping the third temper is the most common cause of premature heat-checking — retained austenite transforms in service, causing dimensional change and surface tensile stresses that open heat-check cracks.
References & International Standards
- ASTM International. Standard Specifications for Steel & Metal Alloys. astm.org
- International Organization for Standardization (ISO). Metallic Materials — Cross-Reference Database. iso.org
- American Iron and Steel Institute (AISI). Steel Grade Designations & Equivalents. steel.org
- European Committee for Standardization (CEN). EN Steel Standards & Numbering System. cencenelec.eu