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8620 Steel | G86200 | A50202: Properties And Products
- John
SteelPro Group offers 8620 steel bars that meet regional standards like ASTM, ISO, and GB. Our products are manufactured with strict tolerance controls to ensure precision and consistency.
What Is 8620 Tool Steel?
8620 steel is a low-alloy, medium-hardening carburizing steel with nickel, chromium, and molybdenum. It provides excellent surface hardness and wear resistance. It offers strong core strength and surface toughness, ideal for medium-strength components like camshafts, gears, and bearings.
Its high nickel content improves toughness compared to other carburizing steels. Although it can be treated with nitriding for added hardness, it does not perform well with flame or induction hardening because of its relatively low carbon content.
What Is 8620 Steel Equivalent to?
Here is the table with the relevant standards and equivalent grades for 8620 steel:
| Country | Standard | Equivalent Grades |
| China | GB/T 3077 | 20CrNiMo/A50202 |
| Japan | JIS G 4053 | SNCM220 |
| USA | ASTM A29/A29M, ASTM A1040, SAE J 404 | (G)8620 |
8620 Steel Products Specification And Sizes
SteelPro Group offers 8620 steel bars in various standard sizes and can also provide custom sizes to meet your specific needs. We’re here to help with the right materials for your project.
Round Bar:
- Diameter: 10 mm to 500 mm (0.4 in to 20 in)
Cold Drawn Bar:
- Diameter: 6 mm to 150 mm (0.24 in to 6 in)
Hollow Bar:
- Outer Diameter: 20 mm to 300 mm (0.8 in to 12 in)
- Wall Thickness: 2 mm to 50 mm (0.08 in to 2 in)
8620 Steel Chemical Composition
| Element | Chemical Composition |
| Carbon (C) | 0.18 – 0.23 % |
| Chromium (Cr) | 0.40 – 0.60 % |
| Iron (Fe) | 96.895 – 98.02 % |
| Manganese (Mn) | 0.70 – 0.90 % |
| Molybdenum (Mo) | 0.15 – 0.25 % |
| Nickel (Ni) | 0.40 – 0.70 % |
| Phosphorus (P) | ≤ 0.035 % |
| Silicon (Si) | 0.15 – 0.35 % |
| Sulfur (S) | ≤ 0.040 % |
8620 Steel Physical Properties
| Property | Metric Value | Imperial Value |
| Density | 7.85 g/cm³ | 0.284 lb/in³ |
| Melting Point | 1425 – 1510 °C | 2597 – 2750 °F |
| Thermal Conductivity | 46.6 W/m·K | 323 BTU·in/hr·ft²·°F |
| Specific Heat Capacity | 0.475 J/g·°C | 0.114 BTU/lb·°F |
| Electrical Resistivity | 0.0000234 ohm·cm | 0.0000234 ohm·cm |
8620 Steel Mechanical Properties
| Property | Metric Value | Imperial Value |
| Tensile Strength | 580 – 800 MPa | 84,000 – 116,000 psi |
| Yield Strength | 310 – 415 MPa | 45,000 – 60,000 psi |
| Hardness (Brinell) | 170 – 280 HB | 170 – 280 HB |
| Hardness (Rockwell C) | 22 – 30 HRC | 22 – 30 HRC |
| Poisson’s Ratio | 0.29 | 0.29 |
| Machinability | 65 % | 65 % |
| Shear Modulus | 80.0 GPa | 11,600 ksi |
| Bulk Modulus | 160 GPa | 23,200 ksi |
| Modulus of Elasticity | 205 GPa | 29,700 ksi |
| Impact Toughness (Charpy) | 40 – 60 J | 29.5 – 44.2 ft-lb |
| Elongation (in 50mm) | 15 – 20 % | 15 – 20 % |
- The machinability is based on 100% machinability for AISI 1212 steel.
8620 Steel Machinability
Working with 8620 steel is typically simpler when it’s in its softened condition. After carburizing and hardening, the surface hardness increases significantly, making it tougher and more resistant to cutting tools. That is why we recommend performing the bulk of the machining before carburizing.
How to Heat Treat 8620 Steel？
Annealing
Heat the steel to between 820°C and 850°C (1508°F and 1562°F) and hold it at this temperature until it is uniform throughout. Afterward, cool it in the furnace or let it air-cool.
Hardening
Heat the steel to 840°C to 870°C (1544°F to 1598°F) for austenitizing, then quench it in oil or water depending on the size and shape of the material. The cooling method depends on the complexity of the part.
Tempering
After hardening, temper the steel at temperatures between 200°C and 700°C (400°F and 1300°F). This improves the toughness of the steel’s surface (case toughness) and reduces the risk of cracks from grinding, without significantly lowering its hardness.
Normalizing
Heat the steel to 910°C (1670°F) and allow it to cool in air. Normalizing improves the machinability of the steel and is often done before carburizing to ensure better performance.
How to Case Harden 8620 Steel？
To case harden 8620 steel, carburizing is used, where the steel is heated to 880°C–900°C (1616°F–1652°F) in a carbon-rich environment. This hardens the surface while keeping the core tough. After carburizing, the steel is quenched and tempered to reduce brittleness, making it ideal for parts like gears and shafts.
For an even harder surface, nitriding can be applied to 8620 steel after hardening and tempering. Nitriding is done at temperatures between 490°C and 530°C (914°F to 986°F), followed by slow cooling to reduce distortion. This process increases surface hardness up to Rc 60 while maintaining the core’s toughness.
We recommend ensuring the tempering temperature is higher than the nitriding temperature for best results.
Welding 8620 Steel
When welding 8620 steel, it’s best to work with it in the annealed or normalized state to avoid cracking. We recommend using welding methods like MIG, TIG or stick welding with the appropriate filler material.
Preheating the steel to 150°C to 200°C (302°F to 392°F) can help prevent cracking, especially for thicker sections. After welding, applying post-weld heat treatment, such as tempering or stress relief, is crucial to restore the material’s characteristics and minimize stress.
What Is 8620 Steel Used For?
AISI 8620 steel is commonly used in a variety of mechanical components that require a balance of toughness, wear resistance, and strength. Here are some specific applications:
- Gears (spur, bevel, differential gears)
- Crankshafts
- Axles
- Shafts (drive shafts, conveyor shafts)
- Bearings
- Camshafts
- Pins and Bushings (piston pins, rocker pins)
- Fasteners (bolts, nuts)
8620 Steel vs 4140 Steel
8620 contains nickel, chromium, and molybdenum, which enhance surface hardness through carburizing. In contrast, 4140 has a higher carbon content and offers higher overall strength without carburizing.
8620 is suitable for components like gears and shafts. 4140, with higher carbon content, offers greater overall strength and is used for parts requiring higher tensile strength, such as crankshafts and heavy-duty shafts.
Premium 8620 Steel Solutions by SteelPro Group
SteelPro Group is a top international provider of premium 8620 steel products. We provide a range of 8620 steel bars in both standard and custom dimensions to suit your particular requirements. Whether for gears, camshafts, or other components, we provide reliable, high-performance materials backed by our expertise.
In addition to 8620 steel, we also offer D2 and H13 tool steels, ensuring high-quality solutions for various tooling applications.
