The standard (often found as an Annex to ) is a technical engineering specification from Mitsubishi Fuso Truck & Bus Corporation that defines general tolerances for machine-cut dimensions
In large-scale automotive manufacturing, consistency across technical drawings is critical for assembly and quality control. The
: It defines strict "allowable leakage" rates. For example, a 12-inch metal-seated valve is allowed up to 480 cc of water leakage per minute at 40 psi—anything more, and it fails the standard. Ms81-2021 Standard Pdf
The 2021 standard likely introduces new symbology or alarm setpoints. Your piping and instrumentation diagrams (P&IDs) must reflect these changes. Additionally, rewrite your standard operating procedures (SOPs) to align with the new testing frequencies.
: Testing the ease of opening and closing the valves. The standard (often found as an Annex to
What is the or country of origin for this standard? (e.g., Malaysia, a specific manufacturer, etc.)
The 2021 revision of the standard (implying an evolution from previous iterations) reflects the advancement of metallurgy and the changing demands of the global supply chain. It likely introduces more stringent testing for hydrogen embrittlement—a phenomenon where hydrogen atoms infiltrate the metal lattice, causing it to become brittle and crack unexpectedly. By codifying the detection and prevention of such microscopic flaws, the standard acts as a barrier against catastrophic failure. It is a shield that operates at the molecular level. The 2021 standard likely introduces new symbology or
The standard specifies permissible deviations for linear dimensions up to 2000 mm when individual tolerances are not indicated on the drawing. Nominal Dimension (mm) 1st Class Tolerance (mm) 2nd Class Tolerance (mm) 6 and under ±0.1plus or minus 0.1 ±0.2plus or minus 0.2 Over 6 up to 30 ±0.2plus or minus 0.2 ±0.5plus or minus 0.5 Over 30 up to 120 ±0.3plus or minus 0.3 ±0.8plus or minus 0.8 Over 120 up to 315 ±0.5plus or minus 0.5 ±1.2plus or minus 1.2 Over 315 up to 1000 ±0.8plus or minus 0.8 ±2.0plus or minus 2.0 Key Application Details