A Fe-Ni-Cr alloy with excellent high temperature oxidation resistance
- Good material for high temperature oxidation resistance
- Maintains high strength at elevated temperatures
- A286 Chemistry, specs, and heat treatments
- A286 flat head screw features and benefits
Flat head screws made from A-286 are known for their high strength, creep resistance and oxidation resistance at elevated temperatures. This iron-nickel-chromium alloy (once age-hardened) provides A-286 screws with high levels of strength from room temperature up to about 1300°F (700°C).
A-286 flat head screws are mildly corrosion resistant. While they should not be used for strong acid environments, they provide excellent oxidation resistance up to 1300°F (700°C) in conditions that would typically be found in high temperature exhaust streams.
Because of these properties, A-286 flat head screws are often found in high temperature engine, manifold, exhaust and turbine applications as well as off-shore oil & gas applications.
Resources: A-286 Torque Specs
A286 flat head screws are characterized by having a head with a top flat surface (which can feature either a slotted, phillips or allen driver) and bottom that is cone shaped or countersunk. With this design, the head of the screw can align flush or below the surrounding surface having obvious benefits.
A286 Slotted vs. Phillips Driver
|Slotted Head Advantages||Phillips Head Advantages|
For most flat head screw designs the angle of countersink is usually 82° for UNC and UNF applications however other angles ranging from 60° -120° could be specified.
|Thread Type||Normal Flat Head Countersink Angle|
UNC / UNF
|ISO Metric / Imperial||90°|
A-286 Heat Treatments: There are several heat treatment combinations for A-286 all with slight variations in performance. They can be specified via an AMS number or a 660 Class: A, B, C or D, with most common specified as class A or D. The A-286 grades A, B and C all have the same min tensile strength and min yield strength of 130ksi and 85ksi respectively. However grade D is significantly better yield with a min tensile of 130ksi and a min yield of 105ksi.
By AMS numbers, the most common for A-286 is AMS 5737 (same as Grade A) and then AMS 5732 (same as Grade B).
A286 Specifications: AMS 5525, AMS 5732, AMS 5737, AMS 5804, EN 1.4980, GE B50T1181, GE B50T12, GE B50T81, UNS S66286, Werkstoff 1.4980