Iso 2768-mk-e Patched -

| Part | Title | Purpose | |------|-------|---------| | | General tolerances for linear and angular dimensions | Defines tolerance classes (f, m, c, v) for sizes, radii, chamfers, and angles | | ISO 2768-2 | General tolerances for geometrical features | Defines tolerance classes (H, K, L) for straightness, flatness, parallelism, perpendicularity, symmetry, runout |

When a designer writes ISO 2768-MK-E in the title block or general notes of a drawing, it instructs the manufacturer that must conform to the specific limits defined by this standard. iso 2768-mk-e

If a feature matters for function or fit, give it an explicit tolerance. ISO 2768-MK-E is for everything else. | Part | Title | Purpose | |------|-------|---------|

| Feature Type | Rule | |--------------|------| | Length, width, height | ± mm from "M" linear table | | Hole diameter | Not covered (size tolerance must be given individually unless it's a general dimension) | | Hole position | Covered by "K" position tolerance (0.5 mm per 100 mm) | | Flatness of a surface | 0.2 mm per 100 mm (class K) | | Perpendicularity of a shoulder | 0.5 mm per 100 mm (class K) | | External fillet radius R5 | ±1.0 mm (since 5 mm is in >3–6 range, "E") | | Chamfer C2 | ±0.5 mm (from "E" table) | | Feature Type | Rule | |--------------|------| |

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 per 100 mm) | Perpendicularity & Symmetry (mm per 100 mm) | Runout (mm) | |----------------|------------------------------------------|----------------------------------------------|--------------| | | 0.2 | 0.5 | 0.2 |