| Tolerance Class | Straightness & Flatness (mm per 100 mm) | Perpendicularity & Symmetry (mm per 100 mm) | Runout (mm) | |----------------|------------------------------------------|----------------------------------------------|--------------| | | 0.2 | 0.5 | 0.2 |
1. Introduction ISO 2768-MK-E is a combined shorthand notation used on engineering drawings and technical documents. It references three parts of the ISO 2768 standard, which specifies default tolerances for linear dimensions, angular dimensions, geometrical features (form, orientation, location, and runout), and the indication of "E" for general external radius and chamfer dimensions. iso 2768-mk-e
For production shops, understanding this shorthand reduces errors and clarifies expectations. For designers, using it correctly (and knowing its limits) produces clear, manufacturable drawings without over-tolerancing. | Tolerance Class | Straightness & Flatness (mm