Engineering
What tolerances can CNC machining achieve?
TL;DR
- Standard CNC tolerance is about ±0.05 mm (±0.002 in).
- High-precision setups reach ±0.01–0.02 mm.
- Tighter tolerances raise cost and inspection time.
CNC machining routinely achieves tolerances around ±0.05 mm (±0.002 in) as a standard, with high-precision setups reaching ±0.01 to ±0.02 mm on critical features. The achievable tolerance depends on machine, material, feature size, and inspection method.
Tighter tolerances cost more because they need slower cuts, finer tooling, and measurement. Unless a feature is functionally critical, designing to a standard ±0.1 mm tolerance keeps cost and lead time down while still being precise for most parts.
Frequently asked questions
What is a "standard" CNC tolerance?
About ±0.05 mm / ±0.002 in on dimensions unless otherwise specified.
Does material affect tolerance?
Yes — stable metals hold tighter tolerances than plastics, which can warp.
How do I specify tolerances?
Call them out on the drawing or in the quote notes for critical dimensions only.