A8 1.2361 Cold Work Tool Steel
A8 cold work tool steel delivers exceptional wear resistance, high toughness and excellent dimensional stability. Perfect for heavy-duty blanking & punching, cold shear blades and structural cold extrusion dies.
- Standard: ASTM A8, DIN 1.2361 , GB 5Cr5WMoSi
- 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 ≤241 HBW; pre-hardened to 56–60 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 AISI A8 in various custom sizes
flat size range
- Thickness: 6-100 mm
- Width: 40-810 mm
block size range
- Thickness: 100-400 mm
- Width: 200-810 mm
round size range
- Diameter: φ10-700 mm
Chemical Composition (%)
Steel Grade | C (%) | Si (%) | Mn (%) | Cr (%) | Mo (%) | W (%) | P (%) | S (%) |
AISI A8 | 0.50-0.60 | 0.75-1.10 | 0.20-0.50 | 4.75-5.50 | 1.15-1.65 | 1.00-1.50 | ≤0.030 | ≤0.030 |
GB 5Cr5WMoSi | 0.50-0.60 | 0.75-1.10 | 0.20-0.50 | 4.75-5.50 | 1.15-1.65 | 1.00-1.50 | ≤0.030 | ≤0.030 |
DIN 1.2631 | 0.45-0.55 | 0.80-1.00 | 0.40-0.60 | 8.00-9.00 | 1.10-1.30 | 1.10-1.30 | ≤0.035 | ≤0.035 |
Main characteristics of A8 tool steel
- Excellent wear resistance - longer tool service life
- Superior toughness - resists chipping and cracking
- Air hardening property - minimal heat treatment distortion
- High compressive strength - withstands heavy working loads
A8 | 1.2361 tool steel applications
A8 steel for Heavy-Duty Blanking & Punching Die
High toughness and good wear resistance make A8 ideal for blanking and punching heavy-gauge sheet metal, resisting chipping under severe shock loads.
A8 steel for Cold Shear Blade
Excellent shock resistance combined with moderate hot hardness ensures reliable edge retention in cold shear blades cutting bars, billets and profiles.
A8 steel for Structural Cold Extrusion Die
Superior toughness withstands extreme radial stress in cold extrusion of structural components, minimizing catastrophic failure risks and extending service life.
Our Production Technology For A8 (1.2631 / X50CrMoW9-1-1) Cold Work Tool Steel
- EAF
- LF
- VD
- Forged or Hot Rolled
- Spheroidizing Annealed
- Machined surface / Peeled
- Ultrasonic testing (UT) 100% as per SEP 1921, ASTM A388, or EN 10308
- Micro Cleanliness as per ASTM E45 Method A (max. thin 1.5, max. thick 1.0)
- Grain size ≥ 6.0 per ASTM E112
- Spheroidized microstructure shall meet the relevant tool steel standards
- Macrostructure, microstructure, grain size, mechanical properties, and cleanliness shall meet the standards specified in GB/T 1299-2025 for Tool and Die Steels
mechanical properties & heat treatment of A8 steel
| Heat temperature | Start forging temperature | Finish forging temperature | Cooling method |
| 1120 – 1150 °C | 1050 – 1100 °C | ≥ 900 °C | Pit or sand cooling |
Annealing
- Heat slowly to 830 – 845°C (1526 – 1553°F) and hold for sufficient time to ensure uniform heating throughout the section (approx. 2 hours per 25mm thickness)
- Cool slowly in the furnace at a controlled rate of ≤ 4°C per hour (or max. 10–20°C/h) down to approximately 500°C
- Further cooling in air to room temperature
- Hardness after annealing: max. 240 HB (approx. 22–23 HRC)
Hardening
-
Preheating (two-stage, recommended):
First stage at 600 – 650°C.
Second stage at 830 – 850°C - Austenitizing temperature: 990 – 1010°C (typical range; lower 980–1010°C also acceptable)
- Holding time: After temperature equalization, hold for 15–30 minutes (or 30 minutes per 25mm of ruling section)
-
Quenching media: Oil, air, or pressurized gas quench.
For cross sections ≤ 127mm (5 inches), cooling in still air is sufficient.
For larger sections, use air blast, pressurized gas, or interrupted oil quench.
For oil quench: quench until black (approx. 900°F/482°C), then air cool - Hardness after hardening: Approx. 56 – 60 HRC (depending on austenitizing temperature and quenching method)
Stress relieving
- Perform after rough machining or heavy stock removal to relieve residual stresses
- Heat slowly to 600 – 650°C (1112 – 1202°F)
- Hold for 2 hours per 25mm of section thickness (minimum 2 hours)
- Furnace cool slowly to approximately 500°C, then air cool
Tempering
- Temper immediately after the workpiece cools to hand-warm temperature (approx. 50–70°C)
- Number of tempers: Minimum 2 times. Double tempering is mandatory for tempering temperatures ≥ 482°C (900°F)
- Holding time: Soak for 1 hour per 25mm of total thickness (minimum 2 hours per cycle)
- Cooling method: Air cool after each tempering cycle
- Optional third temper: Performed at 30 – 50°C below the highest tempering temperature for additional stress relief
Why Choose NSPM as Your A8 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.
