AMS 5860 is a sub-type specification of Custom 455. The alloy is a martensitic age-hardenable multiple-melted stainless steel. Tech Steel & Materials offers the specification in plate, sheet, and strip. The material possesses many favorable characteristics, including high strength at room temperature, excellent corrosion resistance (atmospheric air and freshwater), very good ductility, and toughness.
Furthermore, AMS 5860 is age-hardenable with only one treatment and responds well to hot working and cold working. Specifically, for best mechanical properties, it’s best to heat the material uniformly from 1900 to 2100 °F (1038 to 1149 °C), and then hot work from 1650 to 2300 °F (899 to 1260 °C). Meanwhile, plates and sheets can be cold-rolled before aging to produce even higher strength, in excess of 245 ksi (1689 MPa), while strips can be cold-drawn for the same purpose.
For best strength and toughness, a usual heat treatment at 900 °F / 480 °C, followed by a four-hour air cooling, is recommended. However, depending on the needs, higher temperatures can produce various tensile strengths. The alloy can also be welded adequately using resistance welding and shielded fusion.
AMS 5860 finds use in various industries, including food processing, heat exchangers and conveyors, and the medical industry for devices, instruments, needles, and pins.