Disclaimer: The numerical values in this article are for educational reference. For professional manufacturing and legal compliance, always refer to the latest official ISO 2768-1:1989 and ISO 2768-2:1989 documents.
These define the allowable deviation for shape and orientation: waterson.com : High precision. : Standard precision. : Lower precision. Benefits of Using ISO 2768 General Tolerances to DIN ISO 2768 Iso 2768 General Tolerances Pdf
Angular tolerances are given for the shorter side of the angle (in millimeters per meter or degrees/minutes). Disclaimer: The numerical values in this article are
The standard uses a classification system to define accuracy levels. When used on a drawing, the reference is typically written as , where "m" represents the class for linear/angular dimensions and "k" represents the class for geometric tolerances. Linear and Angular (Part 1): f (fine) m (medium) c (coarse) v (very coarse) General Tolerance - ISO 2768 1 & 2 - ZEISS Quality Forum : Standard precision
By using "customary workshop accuracy" for non-critical features, manufacturers avoid the high costs associated with over-engineering and unnecessary precision. Structure of the Standard
Specifies geometric tolerances (straightness, flatness, perpendicularity, symmetry, and circular run-out). Tolerance Classes