Standard Specification for Free-Machining Ferritic Stainless Soft Magnetic Alloy Bar for Relay Applications

1.1 This specification covers free-machining ferritic stainless soft magnetic alloy produced or supplied expressly in cold-finished bar form for use in magnetic cores and other parts requiring a high permeability, low-coercivity stainless steel.

1.2 Two specific alloy types are covered. The primary constituents are shown in Table 1. These types have corrosion resistance similar to AISI Type 430F and Type 430F, Specification A582/A582M.

1.3 This specification covers only these alloy types supplied in cold-finished bars in cross-sectional shapes such as rounds, squares, hexagons, and octagons with diameters (diagonals) greater than or equal to 0.250 in. (6.35 mm) and less than or equal to 1.625 in. (41.28 mm).²

1.4 Certain cold-finished round bar products are capable of being supplied mill annealed to required magnetic properties such as low coercivity. The size range that can be mill annealed is from 0.250 to 1.625 in. (6.35 to 41.28 mm). Other products of these alloys cannot be mill annealed to produce equivalently low coercivity; hence, the final machined parts should be heat treated as recommended by the producer.

1.5 The values stated in customary (cgs-emu and inch-pound) units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units which are provided for information only and are not considered standard.