Page 718 - ISCAR(TURNING-CATALOG-42-2022)
P. 718

USER GUIDE
      THREADING  The anvil should be selected from the table according to the threading standard. The correct anvil depends on the right







              inclination angle (β) and insert size. The inclination angle (β) is obtained by selecting the thread turning method and finding the
              helix angle (φ) for single-start threading, or lead angle (φL) for the multi-start threading.
              The helix angle (φ) and the lead angle (φL) are determined as exact values by using the formula below or as a
              graph area (see below: Helix (Lead) angle area by using graph, depending on the threading diameter and lead.

                        Helix angle (φ) calculation by using         Lead angle (φ ) calculation by using the
                                                                               L
                        the Single-Start Threading Formula              Single-Start Threading Formula
                                P




                                                                           Lead

                φ=arctan   (      π×Dpitch )                 φ L=arctan    (      π×Dpitch )

                                                             Lead= n×P
               When:                                         When:
               φ    = Helix angle                            φ L  =  Lead angle

               Dpitch = Pitch diameter*                      Dpitch =  Pitch diameter*
               * effective diameter of threading             * effective diameter of threading

               P    = Threading pitch                        P    =  Threading pitch
               π    ≈ 3.142                                  n    =  number of threading starts

                                                             π    ≈  3.142





              Usable formulas

              Lead (inch)=     1 inch   ×No. of starts
                                TPI

              TPI = No. of threading per inch


              1 inch = 25.4 mm


              Pitch (mm)=     25.4
                              TPI





























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