The lead angle effect is a commonly known phenomenon in tool design As the lead angle of a tool (the angle at which the insert is rotated away from its a

The lead angle effect is a commonly known phenomenon in tool design As the lead angle of a tool (the angle at which the insert is rotated away from its a

The lead angle effect is a commonly known phenomenon in tool design. As the lead angle of a tool (the angle at which the insert is rotated away from its axial center line) increases, the actual thickness of the produced chip decreases from the programmed amount. This allows us to take advantage of increased feed rates over standard zero degree (90 degree shoulder) lead tools. By comparing the following lead angle figures, it is possible to increase the actual feed rate up to 30% over the suggested numbers (depending on the type of tool), thus increasing productivity. Tool Lead Angle Percentage of chip thickness from programmed feed rate 15 degrees 96% 20 degrees 94% 30 degrees 86% 45 degrees 71% To simplify this calculation we have included a chart that allows easy determination of programmed feed per tooth by choosing desired feed per tooth and then following the column down to the row that matches the lead angle of the tool that is being used. Example Find the programmed feed per tooth for a UFO cutter (45 degree lead angle), when the desired feed per tooth is 0.006 IPT. Answer Programmed feed per tooth = 0.0085 IPT Programmed Feed Per Tooth vs. Desired Feed Per Tooth Tool Lead Angle Desired Feed Per Tooth (IPT) 0.004 0.005 0.006 0.007 0.008 0.009 0.010 0.011 0.012 Programmed Feed Per Tooth (IPT) 15 0.0042 0.0052 0.0063 0.0073 0.0083 0.0094 0.0104 0.0115 0.0125 20 0.0043 0.0053 0.0064 0.0074 0.0085 0.0096 0.0106 0.0117 0.0128 30 0.0047 0.0061 0.0070 0.0081 0.0093 0.0105 0.0116 0.0128 0.0140 45 0.0057 0.0075 0.0085 0.0099 0.0113 0.0127 0.0141 0.0156 0.0170 590 Technical Guidance INDEXABLE Lead Angle Effect Milling Cutters Lead Angle Effect