The standard focuses on "Go" and "No-Go" gauges, which are used to determine if a part’s dimensions fall within a specified tolerance without providing an actual measurement value.
The JSA is the primary publisher. You can purchase a DRM-protected PDF in Japanese or English. jis b 7420 pdf
: Typically made from tool steel such as SKS31 with a hardness of 58–64 HRC to ensure wear resistance during repetitive use. Gauging Principle : The standard focuses on "Go" and "No-Go" gauges,