A286 / Alloy 660 for excellent high temperature oxidation resistance
- Good material for high temperature oxidation resistance
- Maintains high strength at elevated temperatures
- Specs & heat treatments
- ASTM A453 Grade 660
- A286 chemistry
- Datasheet for A286
A286 bolts, also known as Alloy 660 bolts are stainless steel alloy which contains iron, nickel and chromium. A286 shoulder bolts are known for their high strength, creep resistance and oxidation resistance at elevated temperatures once age hardened. As a result, A286 bolts provide high levels of strength from room temperature up to about 1300°F (700°C).
A286 shoulder bolts 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 of the properties of Alloy 660 / A286 these shoulder bolts 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
A286 shoulder bolts, also called stripper bolts are a unique fastener with three main parts: head, shoulder, and thread. The head has the largest diameter and is where the torque is applied, typically with a socket driver. The shoulder is smooth and unthreaded, and has a set diameter and length. The shoulder’s role is to act as a shaft or dowel for rotating parts, axles for rolling parts, guides for sliding elements, and pivot points. The final part of an A286 / Alloy 660 shoulder bolt is the threaded shaft. The threaded portion of a shoulder bolt has a major diameter slightly smaller than the shoulder diameter.
Material specification ASTM A453 Grade 660 applies to bolts, studs, studs 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