1 Scope
About this parts in GB/T 308 specifies the dimensions, technical requirements, measuring and testing methods, inspection rules, marking and packaging and storage of steel balls.
This Standard is applicable to steel balls for fitting and commercial purposes.
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.
GB/T 3086-2008 High carbon chromium stainless bearing steels;
GB/T 4199-2003 Rolling Bearings--Tolerances--Definitions (IS0 1132-1:2000, Rolling bearings CTolerances--Part 1: Terms and Definitions MOD);
GB/T 6930-2002 Rolling bearings--Vocabulary(IS0 5593: 1997, IDT);
GB/T 7234-2004 Geometrical Product Specifications(GPS)--Measurement of roundness --Terms, definitions and parameters of roundness;
GB/T 7235-2005 Geometrical Product Specifications (GPS)--Methods for the assessment of departure from roundness--Measurement of variations in radius;
GB/T 7811-2007 Rolling bearings--Symbols for quantities((IS0 15241:2001,IDT);
GB/T 8597-2013 Rolling bearings--Rust proof packaging;
GB/T 18254-2002 High-carbon chromium bearing steel;
GB/T 18579-2001 High-carbon chromium bearing steel wires;
GB/T 24606-2009 Rolling bearings-- Non-destructive testing - Magnetic particle testing;
GB/T 24608-2009 Inspection rules for rolling bearings and commercial parts;
JB/T 1255 Specifications for heat treatment of rolling bearing parts made from high-carbon chromium bearing steel;
JB/T 1460-2011 Rolling bearings--Bearing parts made from high-carbon chromium stainless steel--Specifications for heat treatment;
JB/T 2850-2007 Rolling bearings-- Bearing parts made from high temperature bearing steel Cr4Mo4V--Specifications for heat treatment;
JB/T 6641-2007 Rolling bearings—Residual magnetism and its assessment method;
JB/T 7051-2006 Rolling bearing parts--Methods for the measurement and assessment of surface roughness;
JB/T 7361-2007 Rolling bearings--Test method for hardness of parts;
JB/T 10861-2008 Rolling bearings--Atlas and the assessment methods for surface imperfections of steel balls;
YB 688-1976 High temperature bearing steel—Technical Specifications
3 Terms and Definitions
For the purposes of this Standard, the following terms and definitions in GB/T 4199-2003 and GB/T 6930-2002 apply.
3.1 Nominal ball diameter
Diameter value which is used for the general identification of a ball size.
Note: The nominal ball diameter is the general dimension (nominal dimension) of all kinds of ball diameters, it can be rounding off to 4 figures after decimal point.
[GB/T 6930-2002, definition 05.04.01]
