IEC 60740-1:2005 specifies the characteristics of laminations. Their preferred use is cores for transformers and inductors. The laminations are made of sheets and strips of magnetic materials, specified in IEC 60404-8-4 and IEC 60404-8-7. The main changes are listed below: a) ranges with lamination strips YS, YSUI 1, YSUI 2 and laminations YEE 2-..L added; b) range YEI 1 extended at the above end; c) ranges YED 2, YEF 2, YEL 2, YES 2, Type YM 1-5a and YM 1-7a cancelled; d) national designations cancelled; e) electrical characteristics for the laminations specified; f) mechanical characteristics for laminations added; g) holes added for lamination types YEI 1, YUI 1, YUI 2, YM 1; h) in Annex A, a conversion of the polarisation J and the field strength H in a specific total apparent power is defined. For the characteristics of the reactive power and the power loss, equations and constants are specified.