A286 / Alloy 660 for excellent high temperature oxidation resistance
- Excellent high temperature oxidation resistance to 1300°F / 700°C
- Maintains high strength at elevated temperatures
- Specs & heat treatments
- A286 Chemistry
- ASTM A453 Grade 660 and ASTM F2281
- A286 FAQ of the Week
- A286 Datasheet
A286 (1.4980) fasteners, also known as Alloy 660 fasteners are stainless steel alloy which contains iron, nickel and chromium. A286 fasteners are known for their high strength, creep resistance and oxidation resistance at elevated temperatures once age hardened. As a result, A286 fasteners provide high levels of strength from room temperature up to about 1300°F (700°C).
A286 fasteners are also mildly corrosion resistant. While they should not be used for strong acid environments, they provide excellent oxidation resistance up to 1500°F (815°C) in conditions that would typically be found in high temperature exhaust streams. Because A286 fasteners are used in high temperature applications where performance is critical, we can provide fasteners to ASTM A453 Grade 660 in order to ensure accurate standards for tensile and stress rupture properties.
Because of the properties of Alloy 660 / A286, these fasteners are often found in high temperature engine, manifold, exhaust and turbine applications as well as off-shore oil & gas applications. In addition, A286 / Alloy 660 is also non-magnetic and finds a niche in non-magnetic cryogenic equipment.
Resources: A286 Torque Specs
Material specification ASTM A453 Grade 660 applies to bolts, studs, nuts and other fasteners. It ensures fasteners meet strength standards for use in high temperature bolting applications. ASTM A453 Grade 660 is classified into 4 property classes / heat treatments: A, B, C & D, each designated with different tensile and stress rupture properties. The most common of the ASTM 453 classes are class A or D. The grades A, B and C all have the same minimum tensile strength and minimum yield strength of 130ksi and 85ksi respectively. However grade D has a significantly better yield with a min tensile of 130ksi and a min yield of 105ksi.
AMS A286 / Alloy 660 Heat Treatments
By AMS numbers, the most common for A286 / Alloy 660 is AMS 5737 (same as Grade A) and then AMS 5732 (same as Grade B).
A286 / Alloy 660 Cold Worked Fasteners
For additional strength, A286 could be aged and cold worked to achieve a min ultimate tensile strength of 160ksi upon request.
UNS S66286, ASTM A453, AMS 5525, AMS 5726, AMS 5732, AMS 5737, AMS 5804, EN 1.4980, GE B50T1181, GE B50T12, GE B50T81, Werkstoff 1.4980, ASTM F2281
|Inconel 718 Compared to A286 for High Temperature Strength |
Q: We are currently using A286 bolts per ASTM 453 at 1200F and are having some issues with durability as the tensile strength we originally calculated necessary was 130ksi but seems like we need higher strengths. Any ideas?
A: In this type of environment you should consider A-286 in the cold-worked condition. This will give you a minimum tensile of 160ksi. If this is not enough strength, the next step would be Inconel 718 bolts. Inconel 718 can handle the same temperatures as A286 with a usability of up to 1300F. In contrast to A286 screws, Inconel 718 bolts are much stronger with a min tensile 180ksi.