... high permeability, low coercivity, low loss and good stability. Ultra-crystalline Soft Magnetic Alloy Core 1. Material Grade: 1K 107 ... switching power supply, control transformer, precision current and voltage transformer, filter inductor, spike suppressor, energy storage inductor, reactor, magnetic amplifier, ... outside diameter of iron core can up to 1200mm. Ultra-crystalline Soft Magnetic Alloy Core