Surface finish affects aesthetics, friction, and corrosion resistance, but lower Ra values aren’t always better:
Avoid Over-Polishing
Mirror finishes (Ra<0.4μm) require expensive manual polishing. Most industrial parts perform well at Ra1.6-3.2μm.
Consider Texture Direction
Critical for sliding surfaces – specify lay orientation relative to motion.
Account for Post-Processing
Blasting/coating alters surface texture – include finishing allowances.
General Guidelines
Non-contact surfaces: Ra6.3-12.5μm
Standard fits: Ra1.6-3.2μm
Precision bearings: Ra0.4-0.8μm