Aobo Steel supply O1 steel for your project
Premium O1 Tool Steel Supplier for Unmatched Durability
O1 tool steel is a low-alloy cold work die steel. This steel has a certain degree of hardenability and wear resistance, with minimal quenching deformation. The carbide distribution is uniform, and the particles are fine. It is typically used for manufacturing cold punching dies with small cross-sections, complex shapes, and various gauges and measuring tools.
The designation in the U.S. ASTM A681 system is O1. Similar designations in other national standards include ISO 95MnWCr1, Japan/JIS SKS3, USA/UNS T31501, Germany/DIN 100MnCrW4, Germany/W-Nr. 1.2510, and Czech Republic (CSN) 19314. In the following article, O1 steel is used as a substitute.
Most cost-effective, high-quality supplier of D2 steel
We offer both D2 electric furnace steel and D2 ESR steel. Considering our customers’ purchasing costs, we produce D2 round bars with diameters under 200mm using the electric furnace method, which can meet Ultrasonic testing (UT) Sep 1921-84 D/d flaw detection. Customers can purchase high-standard D2 round bars at a lower cost. We adopt the ESR process for diameters above 200mm to ensure that the internal structure can meet Ultrasonic testing (UT) Sep 1921-84 E/e flaw detection.
Excellent D2 Forged Steel Supplier
Aobo Steel has over 20 years of experience in forging D2 steel, giving us a deep practical understanding of quality control in this field. Our D2 forged steel products mainly come in round bar, plate, and block shapes. We have over 40 suppliers providing the best processing services, enabling us to offer advantages such as short lead times, stable quality, and competitive prices.
Suply Range
The shapes of steel that Aobo Steel produces include D2 tool round bars and D2 plates.
| Shape | Size | Length | Surface finish | tolerance |
| round bar | diameter 20mm-400mm | length 2500mm-5800mm | black | 0/+5mm |
| peeled | 0/+5mm | |||
| turned(machined) | 0/+2mm | |||
| plate | width*thickness 100mm-800mm*10mm-400mm | length 2500mm-5800mm | black | 0/+5mm |
| peeled | 0/+5mm | |||
| turned(machined) | 0/+2mm |
O1 tool steel equivalent grades and chemical composition under different standards
| Country | Steel Grade | C | Si | Mn | Cr | W | P | S | V |
| China (GB) | 9CrWMn | 0.85 ~ 0.95 | ≤0.40 | 0.90 ~ 1.20 | 0.50 ~ 0.80 | 0.50 ~ 0.80 | ≤0.030 | ≤0.030 | — |
| USA (AISI) | O1 | 0.85 ~ 0.95 | 0.20 ~ 0.40 | 1.00 ~ 1.30 | 0.40 ~ 0.60 | 0.40 ~ 0.60 | — | — | 0.20 |
| Germany (DIN) | W – Nr. 1.2510 | 0.90 ~ 1.05 | 0.15 ~ 0.35 | 1.00 ~ 1.20 | 0.50 ~ 0.70 | 0.50 ~ 0.70 | P ≤0.035 | ≤0.035 | 0.05 ~ 0.15 |
| JIS | SKS3 | 0.90 ~ 1.00 | ≤0.35 | 0.90 ~ 1.20 | 0.50 ~ 1.00 | 1.00 ~ 1.20 | ≤0.030 | ≤0.030 | Ni,Cu≤0.25 |
Physical Properties
Critical Point Temperatures
| Critical Point | Ac₁ | Ac₃ | Ar₁ | Ms |
|---|---|---|---|---|
| Temperature (approximate value) / °C | 750 | 900 | 700 | 205 |
Forging Process Specifications
| Item | Heating Temperature/°C | Initial Forging Temperature/°C | Final Forging Temperature/°C | Cooling Method |
|---|---|---|---|---|
| Steel Ingot | 1150 ~ 1200 | 1100 ~ 1150 | ≥850 | Slow Cooling |
| Steel Ring | 1100 ~ 1150 | 1050 ~ 1100 | ≥850 | Slow Cooling |
O1 Heat Treatment
Isothermal annealing process after forging
| Process | Heating Temperature (°C) | Holding Time (h) | Tempering Temperature (°C) | Tempering Time (h) | Cooling Method | Hardness (HBW) |
|---|---|---|---|---|---|---|
| Isothermal annealing process after forging | 780 ~ 800 | 2 ~ 3 | 670 ~ 720 | 2 ~ 3 | Furnace cooling to below 550°C, then air cooling | 197 ~ 241 |
Quenching Specifications
| Preheating Temperature (°C) | Heating Temperature (°C) | Quenching Medium | Quenching Medium Temperature (°C) | Quenching Method | Hardness (HRC) |
|---|---|---|---|---|---|
| 650 | 820 ~ 840 | Oil | 20 ~ 60 | Oil Quenching | 64 ~ 66 |
Isothermal quenching process
| Heating Temperature (°C) | Equalizing Temperature (°C) | Equalizing Time (h) | Heat Treatment Structure |
|---|---|---|---|
| 800 ~ 840 | 260 ~ 300 | ≤1 | The base structure is martensite + retained austenite + residual carbide. A suitable amount of bainite is distributed on the high-strength martensite base. |
O1 steel Applications
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Cutting Tools
O1 is widely used for cutting tools such as chisels, drills, and knife blades because it retains a sharp edge. -
Punches and Dies
The toughness and wear resistance of O1 make it a popular choice for punches and dies that endure repeated high-impact forces. -
Knives and Blades
O1 is highly regarded in the knife-making industry for its ability to hold a sharp edge while offering good toughness. This makes it ideal for knives, axes, and other blades. -
Shear Blades
O1 tool steel is often used in shear blades where high hardness and edge retention are critical for cutting through tough materials.
Why should you choose Aobo Steel as your tool steel supplier?
At Aobo Steel, we pride ourselves on our exceptional supply capacity and dedication to meeting customer demands. Our monthly shipments exceed 1,500 tons in the Chinese market, reflecting our robust production and delivery capabilities. With a strong network of over 40 trusted suppliers, we ensure a steady supply of high-quality tool steels to meet various industry needs.
To provide even greater flexibility, we maintain stock for select products, allowing us to fulfill urgent orders quickly. Additionally, we specialize in fully customizable solutions, tailoring our products to your exact specifications for optimal application performance.
Our strategic location near the Yangtze River gives us a significant advantage in export logistics, enabling fast and cost-effective shipping to customers worldwide. Whether you need standard products or custom orders, Aobo Steel is committed to delivering reliability, quality, and service excellence.
At Aobo Steel, quality control is at the heart of our operations. Our dedicated testing team with over 20 years of experience ensures every product meets the highest standards before leaving our facility. Our comprehensive quality assurance process includes chemical composition analysis, metallographic examination, hardness testing, physical performance evaluation, and ultrasonic testing (UT) to detect internal defects.
To guarantee reliability, we perform 100% quality inspection on all products before shipment, ensuring they meet the required specifications and industry standards. Additionally, we support third-party inspections upon request to provide our customers with extra confidence in the quality of our materials. With this rigorous approach, Aobo Steel consistently delivers tool steels that offer superior performance and dependability in various applications.
At Aobo Steel, our service capacity is designed to meet diverse customer needs efficiently and precisely. We provide fully customizable products, offering surface treatments, descaling, and custom-length cutting options to suit specific requirements. Our experienced foreign trade team is well-versed in handling international orders, ensuring smooth communication and seamless transactions.
To provide the best service, we guarantee a 24-hour rapid response to all inquiries, allowing us to address your needs promptly and effectively. At Aobo Steel, we are committed to delivering high-quality tool steels and exceptional customer service to support your success.
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