CNC Machining Tolerances: What You Need to Know

When specifying machined metal components, understanding tolerance classes helps you balance cost with performance. This guide walks through standard tolerance ranges and their practical implications.

Standard vs Precision Tolerances

Standard machining tolerances typically range from ±0.005" to ±0.010", suitable for most structural and non-critical applications. Precision tolerances of ±0.001" or tighter are required for mating surfaces and critical interfaces.

Material Considerations

Different materials behave differently under cutting forces. Aluminum allows tighter tolerances than stainless steel, which tends to work-harden and deflect during machining.

Working with an experienced CNC partner early in the design phase can help optimize your drawings for manufacturability without over-specifying tolerances that drive up cost.