CORE MATERIAL FOR HELICAL WORKING HAVING EXCELLENT MAGNETIC PROPERTY, ITS PRODUCTION METHOD, AND HELICAL WORKED STATOR CORE

PROBLEM TO BE SOLVED: To provide a core material for helical working having excellent magnetic properties which causes no reduction in interlayer resistance, and has low core loss. SOLUTION: The core material for helical working having excellent magnetic properties has a composition comprising, by mass, ≤0.01% C, ≤4% Si, ≤2% Mn, ≤2% Al, ≤0.1% P, ≤0.02% S, and ≤0.005% N, and the balance Fe with inevitable impurities, and in which the crystal grain diameter d (μm) satisfies the ratio between the inside diameter and the outside diameter (inside diameter Di/outside diameter Do) in the core back part of the stator core, and the relation in the inequality (1): d≤20+100×(Di/Do)2(1); wherein, Di is the inside diameter of the stator core (core back part), and Do is the outside diameter of the stator core. COPYRIGHT: (C)2005,JPO&NCIPI