Quality reference

CNC Tolerance Chart

Use tolerance bands to separate normal machining capability from inspection-critical features.

Direct answer: quote tolerance bands should separate normal machining capability from inspection-critical features. Final tolerances must follow the drawing, contract, and quality plan.

Quality reference

CNC Tolerance Chart

Practical tolerance bands for quoting and process planning, with inspection and machine acceptance handoffs.

Source: Created as a planning reference for tolerance-intent support pages after the 2026-06-24 GSC expansion review; final tolerances must follow print and quality-plan requirements.Updated: 2026-06-24

Tolerance band	Typical use	Process implication	Release check
+/-0.25 mm / +/-0.010 in	General machined profile or non-critical clearance	Normal milling or turning capability on stable setups.	Confirm drawing allows general tolerance.
+/-0.10 mm / +/-0.004 in	Fit features and routine datums	Requires stable workholding and controlled tool wear.	Inspect first article and confirm repeatability.
+/-0.05 mm / +/-0.002 in	Precision bores, dowel locations, close fits	May require finish pass, boring, reaming, or probing.	Use calibrated gauge or CMM evidence.
+/-0.025 mm / +/-0.001 in	High-precision bearing and alignment features	Temperature, tool deflection, and machine condition matter.	Verify machine capability and measurement method.
Surface finish callout	Sealing, sliding, cosmetic, or fatigue-sensitive faces	Feed, nose radius, tool wear, and vibration drive result.	Check Ra/Rz requirement with approved instrument.
True position / GD&T	Functional assemblies and datums	Requires datum strategy, fixture control, and inspection plan.	Confirm CMM routine and datum interpretation.