Guide / Surface Finish

CNC Surface Finish Reference

Achieving target surface roughness in turning and milling

Turning Ra vs Feed

Nose Radius	Ra 0.8	Ra 1.6
0.4mm	0.06 mm/rev	0.10 mm/rev
0.8mm	0.10 mm/rev	0.15 mm/rev

Ra = 0.0321 x f^2 / r (f=feed/tooth, r=radius). Stepover for finish: 5-10% of ball end mill diameter.