The iron cores of major Made from stainless steel sheet 0.5 mm Silicon skin nana estimated both sides with electrical insulation coating such as vanich. Bring a soft nest with a cylinder to minimize loss due to a hip hotel ari station ... (Hysteresis loss) and offering flow transmitters (Eddy current loss) in a steel axis. The outer surface of the cylinder, place the Groove (slot) arranged along the circumference of the outer steel axis. To use thousands of coils of major characteristics of the Groove with a 2: konfai in a small blue or high speed machine to use a half-Groove closure, but in a medium-sized or large sky konfai, because the use of a thousand major coils beforehand (coil Form) is required to use an open Groove, steel coils and core features of major.