[国外标准] DIN 472-2009 Retaining rings for bores –Normal type and heavy type
[国外标准] BS 3673.3-1968 Spring retaining rings part3.Carbon steel C clips
[国外标准] JIS B2804-2001 Retaining rings
[国外标准] JIS B2804-1978 英文版 Retaining Rings-C Type