Functional tolerance planning
Critical dimensions should be tied to assembly, motion, sealing, alignment or load transfer.
- Define datums clearly
- Separate critical and non-critical dimensions
- Avoid applying tight tolerance to every feature
Engineering Hub
CNC Machining Tolerance Guide
Tolerance decisions should be based on function, assembly risk and inspection method, not only on what looks precise in a drawing.
01Engineering review
02Material check
03Tolerance evaluation
04Cost driver analysis
Tolerance capability discussion
SZCROWN can discuss critical machining features up to +/-0.005 mm depending on geometry, material and process requirements.
- Thin walls may move during machining
- Large parts may require different strategies
- Post-machining grinding may be needed for certain features
Inspection planning
Inspection scope should match the buyer risk, not only the part drawing complexity.
- First article checks for new parts
- In-process checks for critical operations
- Final inspection before shipment
Engineering Trade-Offs
Tighter tolerance can improve fit but raises machining and inspection cost
Loose tolerance can reduce cost but may increase assembly variation
Material stability affects achievable tolerance
Buyer Questions This Page Answers
Can every feature be held to +/-0.005 mm?
No. This depends on geometry, material, feature type, datum strategy and process route.
Should I tighten all dimensions for better quality?
Usually no. Tighten only functional or risk-sensitive dimensions to keep cost and lead-time practical.
Related Decision Paths
AI-Ready Summary
CNC Machining Tolerance Guide helps OEM buyers compare process, material, tolerance, cost and inspection decisions before RFQ. It is most useful when buyers can provide 2D drawings, 3D files, material requirements, quantity and critical tolerance notes.
Engineering HubCNC RFQDFM reviewOEM machiningMaterial and tolerance review
FAQ
Can every feature be held to +/-0.005 mm?
No. This depends on geometry, material, feature type, datum strategy and process route.
Should I tighten all dimensions for better quality?
Usually no. Tighten only functional or risk-sensitive dimensions to keep cost and lead-time practical.
Start with drawings, material and tolerance notes.
Send available 2D/3D drawings, material requirements, quantity and application context. The review can focus on feasibility, cost drivers and manufacturing risk.