ISO 2768 & GD&T Standard Specifications
Manufacturing Tolerance Standards
Detailed engineering reference tables for CNC machining, 3D printing, sheet metal fabrication, and injection molding tolerances.
CNC Machining Tolerances (ISO 2768-m / ISO 2768-f)
Standard general machining tolerances adhere to ISO 2768 medium (m), with high-precision features holding ISO 2768 fine (f) or custom GD&T down to ±0.005 mm.
| Feature / Dimension Range | Standard Tolerance | High-Precision Tolerance |
|---|---|---|
| 0.5 to 3 mm | ±0.10 mm | ±0.005 mm |
| Over 3 to 6 mm | ±0.10 mm | ±0.008 mm |
| Over 6 to 30 mm | ±0.20 mm | ±0.010 mm |
| Over 30 to 120 mm | ±0.30 mm | ±0.015 mm |
| Over 120 to 400 mm | ±0.50 mm | ±0.025 mm |
| Hole Diameters | H7 / H8 | H6 / ±0.005 mm |
| Surface Roughness (Ra) | Ra 1.6 µm (63 µin) | Ra 0.4 µm (16 µin) |