: It follows the Taylor Principle , where "GO" gauges check the maximum material limit and "NOT GO" gauges check the minimum material limit.
No. Ignoring the legal risk (copyright infringement fines up to $150,000 in the US), the technical risk is too high. File-sharing versions are often the 1987 or 1990 edition. Wear allowances have been updated significantly in the last 30 years. Using an old standard could ruin a batch of expensive parts.
JIS B 7420 specifies the shapes, dimensions, and inspection methods for limit gauges used to check ISO metric screw threads and parallel pipe threads. The standard ensures that male threads (bolts) and female threads (nuts) fit together perfectly without binding or excessive play. The Purpose of Limit Gauges
: The standard defines the correlation between the tolerance zone of the limit gauge and the tolerance of the workpiece, which varies based on whether the nominal size is above or below 180 mm. Where to Access jis b 7420 pdf
The core of the standard revolves around two types of plain limit gauges, often referred to as "GO" and "NOT GO" gauges:
No. While similar, you cannot relabel a plate as JIS B 7420 compliant without testing to the specific flatness criteria and marking requirements of the JIS standard.
If your facility exports to Japan or uses Japanese-designed equipment, adhering to JIS B 7420 is not optional—it is a contractual and legal necessity. : It follows the Taylor Principle , where
In terms of its technical structure, the JIS B 7420 standard spans and aligns with the international standard ISO/DIS 1938-1 (Inspection of plain workpieces - Part 1: Plain limit gauges), ensuring its compatibility with global manufacturing practices.
Gauges themselves are subject to manufacturing variations and wear over time. JIS B 7420 defines:
: Free technical samples showing symbols and definitions are available on PhysicsNorm and NormSplash . File-sharing versions are often the 1987 or 1990 edition
If you search Google for "jis b 7420 pdf free download," you will likely encounter:
Utilize precise gauge tolerances for IT6–IT16 classes as defined in JIS B 0401.
