The is a technical engineering specification used primarily by automotive and heavy machinery manufacturers, such as the Mitsubishi Fuso Truck & Bus Corporation . It defines the permissible deviations for dimensions where no specific tolerance is indicated on a technical drawing, specifically for parts produced via machine cutting . Understanding General Tolerances (Machine Cut)
Note: Many professionals confuse MS81 with ISO 55001 or ANSI/STD-81. While similar in spirit, MS81-2021 specifically refers to the updated machinery lubrication and oil analysis standard developed by the International Council for Machinery Lubrication (ICML) in partnership with technical societies. Ms81-2021 Standard Pdf
Reducing the need to specify tolerances for every single dimension on a drawing, which streamlines the design process. The is a technical engineering specification used primarily