The standard is divided into two parts:
Choosing the right tolerance standard (either ISO 286 or ISO 2768) depends on the specific requirements of the parts being manufactured, the intended use of the parts, and the manufacturing capabilities of the facilities producing them. iso 2768-m tolerances
| Tolerance Class | Straightness & Flatness (mm per 100 mm) | Perpendicularity (mm per 100 mm) | Symmetry & Runout (mm per 100 mm) | |----------------|------------------------------------------|-----------------------------------|------------------------------------| | | 0.2 | 0.3 | 0.2 | The standard is divided into two parts: Choosing
"Because the drawing only called out 2768-m," Elias replied calmly. "We treated it as a size issue until we realized it was a geometry issue. But the 'm' class tolerance gave us the boundary we needed to work within. We fixed the problem, and we stayed inside the standard." But the 'm' class tolerance gave us the
What is ISO 2768? | CNC Machining Tolerance Standards - Fictiv
| Feature | Nominal Size | ISO 2768-m Tolerance | Allowable Range | |-----------------------|--------------|----------------------|-----------------------| | Hole diameter | 20 mm | ±0.2 mm | 19.8 – 20.2 mm | | Step height | 8 mm | ±0.2 mm | 7.8 – 8.2 mm | | Edge chamfer (1x45°) | 1 mm length | ±0.2 mm length | 0.8 – 1.2 mm length | | Perpendicularity | 50 mm height | 0.3 mm over 100 mm | ≤0.15 mm over 50 mm | | Flatness of a plate | 200 mm length| 0.2 mm / 100 mm | ≤0.4 mm total |