Published by the Japanese Standards Association (JSA), establishes specifications for plain limit gauges. These include plain plug gauges, ring gauges, and snap/gap gauges.
When reviewing the technical sheets within a JIS B 7420 document, several critical parameters govern the design and calibration of the gauges: Gauge Tolerance and Wear Allowance
Plain limit gauges. standard by Japanese Industrial Standard / Japanese Standards Association , 01/01/1997. Accuris Standards Store JIS B 7420 - 1997-03-31 - DIN Media
While JIS is domestic, it is often available through international providers like AFNOR .
The standard outlines stabilization processes (sub-zero treatment) to prevent the steel from expanding or contracting over time due to internal microstructural changes.
Official copies are available through the Japanese Standards Association (JSA) .
: Gauges are typically constructed from durable materials like alloy tool steel (e.g., SKS31) with high hardness (HRC 58–64) to resist wear during repeated inspections.
To ensure you have the most accurate and legal version, it is recommended to purchase the standard from reputable sources.
: Establishes standard definitions for measuring instruments like ring gauges and plug gauges. 日本規格協会 JSA GROUP Webdesk Why It’s Essential for Manufacturers Precision Control
The standard outlines how to distinguish between GO and NOT GO gauges, including the use of red marks or specific grooves for NOT GO indicators.
Detailed tables provide the allowed deviations (tolerances) for the gauge's dimension and shape, which must correspond to the grade of hole/shaft tolerance being measured. Why Find the JIS B 7420 PDF?
The Ultimate Guide to JIS B 7420: Standard for Limit Gauges Limit gauges are the backbone of mass production quality control. In the Japanese industrial ecosystem, is the definitive standard that regulates these vital inspection tools.
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)
Whether you are a manufacturing engineer, a quality assurance professional, or a machinist, understanding this standard ensures that your components meet strict dimensional tolerances. What is JIS B 7420?
JIS B 7420:1997 is a critical Japanese Industrial Standard titled "Plain Limit Gauges."
JIS B 7420 outlines several critical parameters to ensure consistency and reliability across manufacturers.
The primary purpose of these tools is to conduct high-speed dimensional inspections on components like shafts and holes without requiring variable measuring instruments. The standard coordinates directly with the standard tolerance classes under the JIS B 0401 classification system. Technical alignment maps closely to the international draft standard ISO/DIS 1938-1 . Key Content in the JIS B 7420 PDF A complete copy of the document includes: JIS-B-7420-1997-1.pdf - PhysicsNorm
Create a laminated summary card of flatness tolerances for your shop floor. This prevents workers from constantly accessing the full PDF.
The is the Japanese Industrial Standard for Plain Limit Gauges , which are tools used to inspect the dimensional accuracy of holes and shafts without a scale. It provides the specifications for design, tolerance, and application of "Go" and "No-Go" gauges for workpieces up to 500 mm in diameter. Scope and Purpose