Standard No.:	GB/T 17951-2005
Chinese Name:	硬磁材料一般技术条件
English Name:	Standard specification for magnetically hard materials
Professional Classification:	K14 Electrician alloy parts
Professional Classification:	GB National Standard
ICS Classification:	29.030
Issued by:
Issued on:	2005-09-19
Implemented on:	2006-06-01
Status:	VALID
Replace:	GB/T17951-2000 STANDARD specifications for magnetically hard materials
Language:	English
File Format:	PDF
Word Count:
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1 Scope
This standard specifies minimum values for the principal magnetic properties of, and dimensional tolerances for, technically important magnetically hard materials (permanent magnets). For information purposes only, the standard provides values for the densities of the materials and the ranges of their chemical compositions
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments (excluding corrections), or revisions, of any of these publications do not apply to this standard. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition applies.

GB/T 2900.60-2002 Electrotechnical terminology—Electromagnetism
(eqv IEC 60050-121:1998)
GB/T 3217-1992 Method of tst of the magnetic properties of permanent magnetic (magnetically hard) materials
GB/T 9637-2001 Electrotechnical terminology--Magnetic materials and components (eqv IEC 60050(221):1990)
GB/T 13888-1992 Methods of measurement of the coercively of magnetic materials in an open magnetic circuit (eqv IEC 60404-7)
JB/T 10102-2001 Magnetic materials: Classification (IEC 60404-1, IDT)

3 Types of materials and their applications

Permanent magnetic materials (magnetically hard materials) are classified in clauses R (magnetically hard alloys), S (magnetically hard ceramics) and U (bonded magnets). Permanent magnets have a coercivity of magnetic polarization >1kA/m. After being magnetized to saturation they produce a material-dependent specific magnetic energy, permanent magnets can be used in equipment and devices based on electromagnetic principles, as well as in mechanical engineering such as holding devices and splints. Further possible and typical applications for the commercially available permanent magnetic materials are described in more detail in JB/T 10102.
4 Classification
4.1 Principal magnetic properties
See Table 1 for the principal magnetic properties, symbols and units
Table 1 CThe principal magnetic properties, symbols and units