When calculating the load on the lead screw, it is necessary to obtain accurate data on the effect of the inertial force that changes with the weight of the object and the speed of movement. Generally speaking, for reciprocating or rotating devices, it is not easy to obtain all the coefficients accurately, such as the shocks when starting and stopping frequently repeated. You can go to Shanghai Manlu to have a look. Their screw rods are OK~ Therefore, if the actual load data is not available, it is necessary to consider the safety factor shown in Table 1 based on experience when selecting the bearing.