Face milling Corner angle and chip thickness When the depth of cut and feed per tooth fz are fixed the larger the corner angle (KAPR) is then the t

Face milling Corner angle and chip thickness When the depth of cut and feed per tooth fz are fixed the larger the corner angle (KAPR) is then the t

Face milling Corner angle and chip thickness When the depth of cut and feed per tooth fz are fixed the larger the corner angle (KAPR) is then the thinner the chip thickness (h) becomes (for a 45 KAPR it is approx. 75% that of a 0 KAPR). Therefore as the KAPR increases the cutting resistance decreases resulting in longer tool life. KAPR:0 KAPR 15 KAPR:45 h0.75fz Effects on chip thickness due to the variation of corner angles Corner angle and crater wear The table below shows wear patterns for different corner angles. When comparing crater wear for 0 and 45 corner angles it can be clearly seen that the crater wear for 0 corner angle is larger. This is because if the chip thickness is relatively large the cutting resistance increases and so promotes crater wear. As the crater develops then cutting edge strength will reduce and lead to fracturing. Corner Angle 0 Corner Angle 15 Corner Angle 45 vclOOm m in Tc69min vc125m/min Tc55min vc160m/min Tc31min SNCM439 287HB DC125mm M20Cemented Carbide ap3.0mm aa110mm fz0.2mmftocrth Workpiece Tools Insert Cutting Conditions Dry Cutting UP AND DOWN CUT (CLIMB) MILLING When choosing a method to machine up cutting or down cut milling (climb milling) is decided by the conditions of the machine tool the milling cutter and the application. However it is said that in terms of tool life down cut (climb) milling is more advantageous. Up Cut Down Cut Tool rotation Milling cutter inserts Portion machined Portion machined Too ratation Milling cutter inserts Q014 TECHNICAL DATA TECHNIC FUNCTION OF TOOL FEATURES FOR FACE MILLING CORNER ANGLE AND TOOL LIFE