1. Put it directly on the U-shaped iron block by manual straightening, then put the flat shovel that has been ground into a circle at the prominent position of the lead screw, beat it with a sledgehammer and straighten it with a dial indicator. This step needs to be repeated many times.
2. If the lead screw is bent as a whole, it needs to be straightened by a press. Similarly, it is necessary to place the lead screw on the U-shaped iron block and place its circular fixture under the lead screw. By observing the straightening effect with naked eyes, you can use a dial indicator to find the alignment, which also needs to be repeated many times.