Tap construction elements (on example of DIN-371) L1 - total length S1 - relief of chamfer L2 - thread length P - pitch of thread L3 - useful length a

Tap construction elements (on example of DIN-371) L1 - total length S1 - relief of chamfer L2 - thread length P - pitch of thread L3 - useful length a - angle of thread L4 - length of driving square Y - rake angle L5 - chamfer length yi - spiral point angle а - size of square 72 - angle of spiral flutes 0d1 - thread diameter к - chamfer angle 0d2 - shank diameter r - straight flute 0d3 - neck diameter X - spiral flute 0d4 - (chamfer) point diameter t - spiral point 0d5 - web (core) diameter z - number of lands m - width of land