Recommendation for Threading Infeed Passes Maintain minimum 0,05mm infeed on last passes to avoid work hardening and excessive abrasion of the thre

Recommendation for Threading Infeed Passes Maintain minimum 0,05mm infeed on last passes to avoid work hardening and excessive abrasion of the threading tool. Constant Volume Infeed Values for Threading Operations In most applications, use of CNC canned cycles produces only marginally successful results. For example, an 8-pitch external thread has a depth of 2mm (.0789"). Aapx ap V nap-1 VT Formula for constant chip load infeed Aap radial infeed x actual pass (from 1 nap number of passes 1st pass, 0.3 2nd pass, 1 3rd pass and up, x Using Radial Infeed Bending stress on the cutting edge caused by V-shaped chips from long-chipping steel workpiece materials. High cutting forces with small cutting thicknesses require sharp edges with high strength. Using Flank Infeed Lower bending stress and stabilised cutting edges produce more favourable chip shapes and larger cutting thicknesses. Carbides with high hardness, good wear resistance, and temperature stability are advantageous. Guidelines for Infeeds How to Determine the Number and the Size of Passes The number of passes s per thread is decisive for successful threading and crest turning. The following tables give standard values for the application condition when machining steel. The proper number of passes must be determined empirically. If insert breakage occurs, the number of passes must be increased. With increased wear, we recommend decreasing the number of passes. The chip thickness should not be less than 0,05mm. The allowance at the diameter should not exceed 0,2mm. Technical Information Widia Threading