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Aobo Steel | Global Tool Steel Supplier in China
AISI O1 Tool Steel | 1.2510 | SKS3
Oil-Hardening Cold Work Steel for Bulk Supply
✓100% UT Tested Quality Assurance
✓SEP 1921-82 Class D/d Guaranteed
✓Annealed State Delivery
✓Surface: Black Scale, Turned, Mill Finish, or Polished
O1 tool steel is a low-alloy cold-worked tool steel. It has a certain degree of hardenability and wear resistance, with minimal quenching deformation. The carbide distribution is uniform, and the particles are fine. Manufacturers typically use tool steel O1 to produce cold-punching dies with small cross-sections, complex shapes, and various gauges, as well as measuring tools. The equivalent grades of O1 are DIN 1.2510 (Germany), JIS SKS3 (Japan), and GB 9CrWMn (China).
Supply Overview
| Grade | AISI O1 / DIN 1.2510 / JIS SKS3 |
| Delivery Condition | Fully Annealed (Soft Condition for Machining) |
| Available Forms | Round Bar / Flat Bar / Plate / Forged Block |
| Monthly Supply Capacity | Stable bulk supply via integrated partner mills (container-level export) |
| Recommended Export Quantity | Full 20GP container (~26 tons) |
| MOQ | 5 tons |
| Lead Time (With Stock) | Approx. 15–25 days |
| Lead Time (Fresh Melt) | 30–45 days |
| Lead Time (Special Route / Higher Cleanliness) | Approx. 45–60 days (upon request) |
| Inspection | In-house UT + Third-party inspection available |
| Documentation | MTC (EN 10204 3.1) + UT Report (if UT is required) |
Production Stability
- Stable bulk supply for distributor replenishment (MOQ 5 tons)
- Annealed-state delivery for reliable machining and scheduling
- Flexible production routing for different section sizes
- Stable alloy sourcing to reduce supply interruption risk
- Full batch traceability linked to the original heat number
Packaging and Shipping
- Seaworthy export packing for long sea transit
- 20GP loading optimized up to ~26 tons
- Mixed sizes supported for stocking orders
- Anti-rust protection available upon request
For international orders, full container loading is recommended for better freight efficiency and smoother customs clearance.
AISI A2 Tool Steel | 1.2363 | SKD12 Gallery
Applications
- Dies & Punches: Blanking dies, Coining dies, Drawing dies, Forming dies, General Stamping (punches & dies for short/moderate runs), Thread-rolling dies, Cold-trimming dies
- Cutting & Machining Tools: General shop tool bits (economical choice), Shear blades (especially smaller ones), Taps, Reamers, Hobs, Slitting saws, Circular cutters, Drills
- Molds & Precision Parts: Plastic mold components (inserted cavities, master hubs), Gauges, Master tools
- General Tooling & Wear Parts: Cams, Bushings, Guides, Plain sliding bearings, Cam followers, Burnishing tools, Knurling tools, Feed rolls, Roll forming tooling (moderate runs)
O1 Steel and Its Equivalent Grades’ Composition
| C | Mn | Si | Cr | W | V | Ni | Mo | P | S |
| 0.85 – 1.00% | 1.00 – 1.40% | Max 0.50% | 0.40 – 0.60% | 0.40 – 0.60% | Max 0.30% | Max 0.30% | Max 0.30% | Max 0.03% | Max 0.03% |
The O1 tool steel equivalent grades’ composition
| Grade | Standard | C (%) | Si (%) | Mn (%) | Cr (%) | W (%) | V (%) |
| 1.2510 | DIN | 0.90-1.05 | 0.15-0.35 | 1.00-1.20 | 0.50-0.70 | 0.50-0.70 | 0.05-0.15 |
| SKS3 | JIS | 0.90-1.00 | ≤0.35 | 0.90-1.20 | 0.50-1.00 | 0.50-1.00 | – |
| 9CrWMn | GB | 0.85-0.95 | ≤0.40 | 0.90-1.20 | 0.50-0.80 | 0.50-0.80 | – |
All O1 materials are produced in strict accordance with the specified chemical composition requirements of AISI O1, DIN 1.2510, and JIS SKS3 standards.
Properties
- Strength (Tensile and Yield): Tool steel O1 exhibits a tensile strength of 846 MPa and a 0.2% Offset Yield Strength of 829 MPa, with a general yield strength of 758 MPa. For a specific O1 composition, tensile strength can reach 1725 MPa (250 ksi) when tempered at 800°F (425°C), decreasing with higher tempering temperatures.
- Ductility and Toughness: O1 steel exhibits noticeable necking before fracture, with a substantial area reduction at fracture of nearly 20%. Its fracture surface typically displays a cup–cone mode. While generally medium-tough, it shows superior impact strength compared to other O-type steels within the common working hardness range of 57 to 64 HRC. Ductility usually increases with increasing tempering temperature.
- Modulus of Elasticity: 211 GPa.
- Dimensional Stability: Good dimensional stability during heat treatment. When oil-quenched from the correct hardening temperature, it typically expands by about 0.0015 inches per inch (0.0015 mm/mm). However, factors like part geometry and distortion (bending, bowing, or twisting) can influence the final dimensional changes.
- Machinability: Very good machinability. If the machinability of steel with 1% carbon content is set at 100, the machinability of O1 steel is 90.
O1 Heat Treatment Overview
O1 is an oil-hardening cold work tool steel supplied in the fully annealed condition. Proper heat treatment is required to achieve its typical working hardness and dimensional stability.
Typical Heat Treatment Parameters (Reference)
| Process Step | Typical Temperature | Notes |
|---|---|---|
| Preheating | 600–650°C (1110–1200°F) | Equalize temperature, reduce thermal shock |
| Austenitizing | 800–820°C (1470–1500°F) | Soak ~5 min per inch (25 mm) section |
| Quenching | Oil | Quench to 50–65°C (120–150°F) before tempering |
| Tempering | 150–200°C (300–390°F) | 2 hours per inch (25 mm) section |
Typical Achievable Hardness
- As-quenched: 62–64 HRC
- After tempering: 57–62 HRC
Hardness will vary depending on section size and tempering temperature.
O1 is less distortion-sensitive than water-hardening grades but requires controlled oil quenching to minimize the risk of cracking. Double tempering may be recommended for improved dimensional stability in precision tooling applications.
For full heat treatment curves, soaking calculations, tempering response charts, and metallurgical explanation, please refer to: Complete O1 Heat Treatment Guide