Nickel-iron alloy 1J85 (Supermalloy) is a soft magnetic alloy with about 80% nickel and 5% molybdenum. It offers very high permeability and low coercivity for weak-field shielding, sensors, and transformers.
1J85 (Supermalloy, Ni80Mo5) is a soft magnetic nickel-iron-molybdenum alloy (about 80% nickel, 5% molybdenum), a close relative of 1J79 with slightly more molybdenum, and is valued for very high permeability and very low coercivity in weak magnetic fields.
Like 1J79, it saturates at a low flux density (about 0.7–0.8 T), and its magnetic properties are very sensitive to internal stress, so machined parts depend on a high-temperature anneal.
1J85 is a good option for magnetic shielding, sensitive sensor cores, and relay or audio transformer parts.