(1) Branching method and correct branching. If the line dividing method is not selected properly, the line dividing operation is not correct, and the line dividing error occurs, the pitch of the multi-thread thread being turned will be unequal, which will seriously affect the screwing accuracy of the internal and external threads and reduce the service life.
(2) The adjustment of the exchange gear of the lathe should be determined according to the lead, and the position of the handle of the lathe should be adjusted correctly.
(3) The lead of the multi-thread thread is relatively large, and special attention should be paid to the influence of the lead on the relief angle of the two cutting edges of the tool. The helix angle should be calculated according to the lead, and attention should be paid when sharpening.
(4) When fine turning multi-thread threads, it is necessary to finish turning after all the helical grooves are rough turned, otherwise, it is difficult to ensure the consistency of the thread profile.
