Aobo Steel supply O2 steel for your project
Premium O2 Tool Steel Supplier for Unmatched Durability
O2 tool steel has high hardness and wear resistance. It experiences minimal distortion during quenching and has excellent hardenability. This steel is suitable for making various precision measuring tools and templates. It is also used for smaller-dimension dies, cold press molds, engraving molds, and blanking dies. Additionally, it can be used for machine tool screws and other structural components.
The designation is O2 in the U.S. ASTM A681 system. Similar designations under other national standards include ISO 90MnV2, USA/UNS T31502, Germany/DIN 90MnCrV8, and Germany/W-Nr. 1.2842. In the following article, O2 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.
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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 |
O2 tool steel equivalent grades and chemical composition under different standards
| Standard | Grade | C | Mn | V | Cr | Si | P | S | Mo |
| ASTM A681:2007 | O2/T31502 | 0.85 ~ 0.95 | 1.40 ~ 1.80 | ≤0.30 | ≤0.50 | ≤0.50 | ≤0.030 | ≤0.030 | ≤0.030 |
| ISO 4957:1999 | 90MnV2 | 0.85 ~ 0.95 | 1.80 ~ 2.20 | 0.05 ~ 0.20 | 0.20 ~ 0.50 | 0.10 ~ 0.40 | ≤0.030 | ≤0.030 | — |
| EN ISO 4957:2001 | 90MnCrV8 /1.2842 | 0.85 ~ 0.95 | 1.80 ~ 2.20 | 0.05 ~ 0.20 | 0.20 ~ 0.50 | 0.10 ~ 0.40 | ≤0.030 | ≤0.030 | — |
| GB/T 1299—2000 | 9Mn2V /T20000 | 0.85 ~ 0.95 | 1.70 ~ 2.00 | 0.10 ~ 0.25 | — | ≤0.40 | ≤0.030 | ≤0.030 | — |
Critical temperature
| Ac1 (°C) | Accm (°C) | Ar1 (°C) | Ar3 (°C) | Ms (°C) | |
|---|---|---|---|---|---|
| Temperature (Approximate) | 730 | 760 | 655 | 690 | 125 |
Forging Process
| Item | Heating Temperature (°C) | Initial Forging Temperature (°C) | Final Forging Temperature (°C) | Cooling |
|---|---|---|---|---|
| Steel Ingot | 1140 ~ 1180 | 1100 ~ 1150 | ≥850 | Slow Cooling |
| Steel Billet | 1080 ~ 1120 | 1050 ~ 1100 | ≥850 | Slow Cooling |
O2 Heat Treatment
Annealing process
- Heating temperature: 750 ~ 770°C
- Holding for: 3 ~ 5 hours
- Equalizing temperature: 680 ~ 700°C
- Holding for: 4 ~ 6 hours
- Annealing hardness: less than or equal to 229HBW
Quenching process
- Normal quenching heating temperature: 780 ~ 820°C
- Oil quenching or nitrate-graded quenching
- Hardness reaches: above 62HRC
- The microstructure of 9Mn2V steel quenched at 780°C is martensite + retained austenite + residual carbides
- Quenching hardness: about 65HRC
- Bending strength (σ_bb): about 2058MPa, which is the highest quenching hardness and bending strength
- When O2 steel is quenched at 820°C, the quenching hardness drops to 64.5HRC, and the bending strength (σ_bb) drops to 2009MPa
Tempering Process
The tempering resistance of 9Mn2V steel is relatively poor, and the hardness can drop below 60 HRC after tempering at 200°C. The tempering temperature generally requires air cooling between 160-180°C, with a hardness of 60-62 HRC. Tempering brittleness and significant volume swelling should be prevented when the tempering temperature is 200-300°C.
O2 steel Applications
Cutting Tools
O2 is widely used to manufacture cutting tools such as chisels, drills, and metal cutting saw blades because it maintains a sharp edge.Punches and Dies
O2’s toughness and wear resistance make it ideal for producing punches and dies that can withstand high-impact forces and wear.Knives and Blades
O2 tool steel is a popular choice for knife makers and those requiring precision cutting due to its sharpness and durability.Cold Forming Tools
O2 is used for cold-forming tools subjected to high mechanical stress and requiring exceptional wear resistance.
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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