GB/T 43344-2023 Specification for magnetic materials (iron and steel) for use in relays
1 Scope
This document specifies the general requirements, magnetic properties, geometric characteristics and tolerances as well as inspection procedures for magnetic materials used primarily for relays.
This document applies to pure iron, non-alloyed and alloyed steel and ferritic stainless steel products usually delivered in either the semi-processed or fully-processed state.
Note: These materials correspond to classes A, B, C and D.3 of IEC 60404-1.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 286-1 ISO system of limits and fits - Part 1: Bases of tolerances, deviations and fits
ISO 404 Steel and steel products - General technical delivery requirements
ISO 10474 Steel and steel products - Inspection documents
IEC 60050-121 International Electrotechnical Vocabulary - Part 121: Electromagnetism
IEC 60050-221 International Electrotechnical Vocabulary - Chapter 221: Magnetic materials and components
IEC 60404-1 Magnetic materials - Part 1: Classification
IEC 60404-7 Magnetic materials - Part 7: Method of measurement of the coercivity of magnetic materials in an open magnetic circuit
IEC 60404-9 Magnetic materials - Part 9: Methods of determination of the geometrical characteristics of magnetic steel sheet and strip
3 Terms and definitions
For the purpose of this document, the definitions of the principal terms related to magnetic
properties given in IEC 60050-121, IEC 60050-221 and IEC 60404-9 apply, as well as the
following definitions:
3.1
sheet and plate
flat rolled product with a minimum width of 600 mm
Note 1: The edges may be as rolled, mechanically sheared or flame cut.
Note 2: The distinction between sheet and plate is principally in terms of thickness tolerances (see Tables 3 and 4). Further information can be found in ISO 6929.
3.2
strip
flat rolled product which, immediately after the final rolling pass or after pickling or continuous annealing, is wound into a regular coil
Note: As rolled, strip has slightly convex edges; strip may also be supplied with sheared edges or slit from wider strip.
3.3
flat
bar of rectangular cross-section, rolled on the four faces, whose thickness is generally 5 mm or greater and whose width is not greater than 150 mm
3.4
round
bar having a circular cross-section whose diameter is generally 8 mm or greater
3.5
square
bar having a square cross-section whose side dimension is generally 8 mm or greater
3.6
wire rod
hot-rolled long product whose nominal size is generally 5 mm or greater, wound into irregular coils
Note: The cross-section may be round, oval, square, rectangular, hexagonal, octogonal, half-round or of any similar shape.
3.7
wire
product of constant full cross-section along its length, obtained by cold-drawing which can be wound into irregular or regular coils
Note: It is obtained by cold-drawing wire rod through a reducing die or passing it under pressure between rollers and rewinding the drawn product.
4 Classification
The materials covered by this standard are classified according to the maximum value of
coercivity, the shape and dimensions of the material and its final condition and state. Not all materials are available in the cold-rolled condition throughout the thickness range.
