Parts for ToolsTechnicalReference øDøD øb h øa User’s Guide - Technical Reference Tu r n i n g To o l s Calculation formulas for turning ᭹Cutting speed When calculating cutting speed from number of revolutions: Externalturning n Vc = π × øD × n Vc : Cutting speed (m/min)n:Number of revolution (min-1) 1000 øD : Diameter of workpiece (mm) π53.14 When calculating required number Example : Calculating the cutting Internal of revolutions from cutting speed: speed when turning a ø150 mm- turning diameter workpiece at 250 min-1 n n = Vc × 1000 Vc = 3.14 × 150 × 250 = 117 m/min π × øD 1000 ᭹Cutting time on external and internal turning T: Cutting time (min) Externalturning R T(min) Rfn R: Cutting length (mm)f:Feed (mm/rev) n: Number of revolution (min-1) Internal turning R ᭹Cutting time on face turning T øa 2− øb 2 Vc : Cutting speed (m/min)f:Feed (mm/rev) (min) T: Cutting Time (min) ᭹Theoretical surface roughness h : Surface roughness (µm) f f : Feed (mm/rev) (μm) xr r : Nose radius (mm)〔RE〕 〔 〕The notation in the brackets is the one RE used in the catalog (ISO compliant) ᭹Calculation of power consumption (kW) Pc : Power requirement (kW) F x Vc F : Cutting force (N) Vc : Cutting speed (m/min) L030 www.tungaloy.com