The permissible deviation increases as the nominal length of the part increases. For example, in typical tables for Class B: Up to 30 mm: Over 1000 to 2000 mm: Over 4000 to 8000 mm: Modern Equivalent: ISO 13920 If you are working on a new design, you should use
DIN 8570 was a historical German standard for , which has since been superseded by the international standard ISO 13920 . It established standardized accuracy levels for linear and angular dimensions, as well as shape and position, to simplify technical drawings. The Role of Tolerance Class B din 8570 b pdf