CHIP SURFER & ROUND LINE GENERAL FORMULA FOR MILLING OPERATIONS Explanation of catalog parameters and formula symbols Symbol Unit Designation D inch Nominal diameter n min-1 RPM ae inch Width of cut ap inch Cutting depth fz inch Feed per tooth f mm/U Feed per revolution hm inch Average chip thickness Pc kW Spindle power consumption Q ft3/min Chip removal rate vc ft/min Cutting speed vf in/min Feed rate C x 45° Chamfer R – Radius 454