Torque Required to Raise Load by Square Threaded Screws
The torque required to raise a load by means of square threaded screw may be determined by
considering a screw jack as shown in Fig. 17.2 (a). The load to be raised or lowered is placed on the
head of the square threaded rod which is rotated by the application of an effort at the end of lever for
lifting or lowering the load.
may be cut by means of dies and hence it is more easily
manufactured than square thread. The standard dimensions
for acme or trapezoidal threads are shown in Table