Specifications for Spring Wire

Two tempers exists, the most common Inconel X-750 is precipitation heat treated to a spring temper condition. In this state, it has temperature resistance to 700° F. The National Association of Corrosion Engineers (NACE) approves this hard temper to Specification MR-01-75 (Rc 50 maximum) for compression springs. No.1 temper has a lower tensile strength but provides temperature protection to 1000°F. Both spring temper and No.1 temper may be heat treated in either an open air or atmosphere controlled furnace. Open air heat treatment may produce oxidation which often results in a black ash residue. An atmosphere controlled environment eliminates oxidation and produces a component with no residue. Rings and springs manufactured from Inconel have a blue / silver-gray color and exhibit no magnetism.