H21 1.2581 SKD5 hot work tool steel
1.2581 tool steel is a premium high-tungsten hot work grade with exceptional red hardness, wear resistance and thermal stability for hot forging, extrusion and die casting tools.
- Standard: EN X30WCrV9-3, AISI H21, DIN 1.2581, JIS SKD5, GB 3Cr2W8V
- Technique: EAF + LF + VD or ESR, forged, multi-directional forging ratio ≥4, stress-relief annealed
- Shape: Round, Flat, Plates, Blocks
- Heat treatment: Supplied in annealed condition, hardness ≤229 HBW; pre-hardened to 44–50 HRC (quenched and tempered) available on request
- Surface Treatment: Black (hot-rolled / forged surface), turned, milled / ground, sawn ends
- Tolerance: flat bars & plates thickness: +0.5/-0.0 mm (turned); forged blocks: ±0.2 mm
- MOQ: 1 Ton
We supply DIN 1.2581 in various custom sizes
flat size range
- Thickness: 6-200 mm
- Width: 40-1200 mm
block size range
- Thickness: 200-500 mm
- Width: 300-1000 mm
round size range
- Diameter: φ10-700 mm
Chemical Composition (%)
Grade | C | Si | Mn | Cr | W | V | P (≤) | S (≤) |
1.2581 (X30WCrV9-3) | 0.25–0.35 | 0.15–0.35 | 0.20–0.40 | 2.50–3.20 | 8.50–9.50 | 0.30–0.45 | 0.030 | 0.020 |
H21 | 0.26–0.36 | 0.15–0.40 | 0.15–0.40 | 3.00–3.75 | 8.50–10.00 | 0.30–0.60 | 0.030 | 0.020 |
SKD5 | 0.25–0.35 | 0.10–0.40 | 0.15–0.45 | 2.50–3.20 | 8.50–9.50 | 0.30–0.50 | 0.030 | 0.020 |
3Cr2W8V | 0.30–0.40 | 0.20–0.40 | 0.20–0.40 | 2.20–2.70 | 7.50–9.00 | 0.20–0.50 | 0.030 | 0.020 |
Main characteristics of 1.2581 tool steel
- High temp strength - retains hardness under red heat
- Excellent temper resistance - resists softening at high temps
- Good dimensional stability - minimal distortion when hardening
- Thermal shock sensitive - requires preheating, no water cooling
H21 | 1.2581 | SKD5 tool steel applications
1.2581 steel for Hot Extrusion Die
Excellent hot strength and high toughness keep 1.2581 dies performing reliably under sustained thermal and mechanical loads in aluminum profile extrusion.
1.2581steel for Hot Forging Die
Superior resistance to heat checking and thermal shock makes 1.2581 ideal for demanding hot forging, extending die life under severe temperature cycling.
1.2581 steel for Hot Trimming Die
Outstanding toughness combined with good wear resistance withstands the heavy impact and abrasion of hot trimming forged parts.
Our Production Technology For 1.2581 (X30WCrV9-3 / H21) Hot Work Tool Steel
- EAF
- LF
- VD
- ESR
- Forged
- Spheroidizing Annealed
- Machined surface
- Ultrasonic testing (UT) 100% as per SEP 1921 Class 3 D/d, E/e or ASTM A388.
- Spheroidized microstructure as per standard NADCA#207-2003 or similar.
- Macrostructure, microstructure, grain size, and impact toughness shall meet the standards specified in GB/T 1299-2025 or AISI H21 specifications.
- Delivery Condition: Soft annealed, max. 240 HB
mechanical properties & heat treatment of 1.2581 steel
| Heat temperature | Start forging temperature | Finish forging temperature | Cooling method |
| 1130 – 1150 °C | 1100 – 1150 °C | ≥ 900 °C | Pit or sand cooling |
Annealing
- Heat slowly to 780 - 840°C (1436 - 1544°F)
- Hold at temperature for 2–4 hours, depending on section thickness
- Cool slowly in the furnace at a controlled rate of max. 10–20°C/h down to approximately 500°C (932°F)
- Then air cool to room temperature. Hardness after annealing: max. 240 HB (approximately 22–23 HRC)
Hardening
- Preheating (required) : Heat slowly to 600 - 650°C (1112 - 1202°F) and hold for 30 minutes per 25mm of thickness
-
Austenitizing temperature : 1070 - 1150°C (1958 - 2102°F). Depending on application, the temperature range is:
1050 - 1130°C for typical applications.
1100 - 1150°C to maximize hot strength.
1060 - 1120°C for hot bath and pressurized gas quenching.
1075 - 1125°C for oil quenching - Holding time: After reaching the hardening temperature, hold for 15–30 minutes, depending on the cross-section of the workpiece
-
Quenching media: Oil, air, warm bath, or pressurized gas (high-pressure gas quench).
For large cross-sections, oil quenching is recommended to ensure through-hardening.
For smaller, less complex shapes, air cooling (using compressed air) may be sufficient - Hardness after quenching: 47 - 56 HRC (typically 50 – 54 HRC)
Stress relieving
- Perform after rough machining, heavy stock removal, or extensive machining to reduce the risk of distortion during final heat treatment
- Heat carefully to 650°C (1202°F)
- Hold for 1–2 hours (or 2 hours per 25mm of section thickness)
- Cool in still air
Tempering
- Temper immediately after the workpiece has cooled to a hand-warm temperature (approx. 50–70°C)
- Number of tempers: Minimum 2 times. Double tempering is mandatory for tungsten hot work tool steels
- Holding time: Hold for 1 hour per 20mm of section thickness, but at least 2 hours per cycle. Air cool after each tempering cycle
- Third temper (optional) : For additional stress relief, a third temper may be performed at 30–50°C below the highest tempering temperature used
Why Choose NSPM as Your 1.2581 Tool Steel Supplier
Source Direct
Direct mill cooperation ensures stable supply, competitive pricing, and consistent quality. Global resource integration and strong supply chain management guarantee reliable material sourcing and long-term availability.
Stock Ready
50,000+ tons inventory across 11 warehouses enables fast delivery. Flexible cutting, short lead times, and ready stock support urgent demands and improve customers’ production efficiency.
Expert Team
600+ professionals, including R&D specialists and technical engineers, provide application-driven support. Fast response and deep tooling knowledge ensure accurate solutions for diverse industrial needs.
Fully Inspected
Strict quality control system with full traceability, UT testing, and heat treatment records. Certified standards (ISO, CE) ensure every material meets high-performance and reliability requirements.
Full-Chain Machining
From steel supply to precision machining, heat treatment, and equipment manufacturing, NSPM offers integrated solutions that enhance accuracy, efficiency, and overall tooling performance.
