Jis B 7420 Pdf |link| Here

of the part. Its length should ideally match the length of the hole or shaft being inspected. NOT GO Gauge : Designed based on the Least Material Limit (LML)

No, but they are related. ISO 1938 covers inspection of plain workpieces. JIS B 7420 is more specific to the gauge itself . In many cases, JIS B 7420 is harmonized with ISO standards, but there are distinct differences in wear limits and tolerance classes. Never assume they are interchangeable. jis b 7420 pdf

: JIS B 7420 accounts for the gradual wear of "Go" gauges by allowing a specific portion of the tolerance zone for "permissible wear," ensuring the gauge remains valid over time. NormSplash Gauge Types and Design of the part

The standard provides specific formulae (found in Table 5 of the document) and attached tables to calculate the exact size of a limit gauge based on the workpiece's nominal size and tolerance grade. When dimensions reach five or more decimal places, they are rounded to four places according to . How to Access the JIS B 7420 PDF ISO 1938 covers inspection of plain workpieces

There are three primary reasons engineers search for this document:

The most direct source is the JSA group.