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CNC Machining Tolerance Standards

General tolerances according to ISO 2768-1. Unless otherwise specified on the drawing, we default to ISO 2768-m (Medium).

Technical Reference

Linear Dimensions (ISO 2768-1)

Size Range (mm) Fine (f) Medium (m) Coarse (c)
0.5 - 3 ± 0.05 ± 0.1 ± 0.2
3 - 6 ± 0.05 ± 0.1 ± 0.3
6 - 30 ± 0.1 ± 0.2 ± 0.5
30 - 120 ± 0.15 ± 0.3 ± 0.8
120 - 400 ± 0.2 ± 0.5 ± 1.2
Default: Alloyer defaults to ISO 2768-m. For features that require tighter tolerances (e.g., +/-0.01mm for press-fits), please include a 2D PDF drawing with your STEP file.