Alloy 8620 Aircraft Quality (AQ) is a premium carburizing alloy steel engineered for demanding applications that require exceptional toughness, strength, and wear resistance. Featuring a hard case and durable core after heat treatment, 8620 AQ is widely used in gears, shafts, pinions, and other power transmission components. Its enhanced cleanliness and quality controls help ensure reliable performance in aerospace, defense, and critical industrial applications
Compared to commercial-grade 8620, Aircraft Quality 8620 is produced to tighter chemistry and cleanliness requirements, resulting in improved consistency and performance in highly stressed components. The alloy offers an excellent balance of machinability, hardenability, fatigue resistance, and core toughness, making it a preferred choice for parts subjected to repeated loading, shock, and wear. These characteristics have made Alloy 8620 AQ a trusted material for aerospace hardware, landing gear components, drivetrain systems, bearings, and precision-engineered industrial equipment where long-term reliability is essential.
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AISI 8620 Chemical Composition
Chemical Composition (wt%) limits of AISI 8620*
| Carbon | 0.18-0.23 | Nickel | 0.40-0.70 |
| Manganese | 0.70-0.90 | Molybdenum | 0.15-0.25 |
| Silicon | 0.15-0.35 | Phosphorus | 0.025 |
| Chromium | 0.40-0.60 | Sulfur | 0.025 |
*Maximum, unless range is indicated
AISI 8620 Physical Properties
| Density, lb/in3 | 0.284 |
| Modulus of Elasticity, psi | 29 x 106 |
| Coefficient of Thermal Expansion, 68-212˚F, /˚F | 6.5-6.8 x 10-6 |
| Thermal Conductivity, Btu/ft hr ˚F | 30.0 |
| Specific Heat, Btu/lb ˚F | 0.114 |
| Electrical Resistivity, Microhm-in | 6.4-6.5 |
Alloy 8620 AQ Standards
| AMS 6274 |
| AMS 6276 |
| AMS 6277 |
| SAE/AISI 8620 |
Your Source for Alloy 8620 AQ
At Double Eagle Alloys, we supply 8620 alloy steel in long bar engineered for these demanding services. Contact our team to learn how 8620 alloy steel can support long-term performance and reliability.
Questions? We’d love to help. Contact us today to discuss your needs or to check current availability.
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Data shown are typical and provided for informational purposes only. Values should not be considered minimums or maximums for specification or final design. Actual product data may vary, and information may be revised without notice.