Permanent Magnets Ltd. supplies tape-wound 80% NiFe Toroidal Cores to industries requiring High Metering Accuracy (HMA) current transformer cores. 80% NiFe has High permeability, Low magnetization in higher inductions and High saturation flux density. By properly heat treating in a controlled hydrogen atmosphere furnace, (to a soft magnetic anneal) we maintain close control of the magnetic properties over a broad range of flux densities which permits the most economical and efficient design of your transformer. The Toroidal wound cores are made robust by finishing them with varnish coating with or without plastic casing. They are available in comprehensive range of sizes.We offer a range of wound cores from minimum 1” [25 mm] inside diameter to maximum 47.25” [1200 mm] outside diameter, using 80% NiFe foil thicknesses ranging between 0.004” [0.1 mm] and 0.014” [0.36 mm] . Core height is available from .200” to 2” [5-50 mm] .