Swing shears (a kind of shears) on the aluminum plate casting and rolling mill in our factory often get stuck during work. What is the reason?

This is not the problem of the blades, but the problem of verticality deviation formed when the upper and lower blades are installed. Generally, the upper and lower blades form an included angle before cutting at the intersection of the upper and lower blades, and then the included angle at the intersection basically reaches 0, and a negative included angle is formed after cutting at the intersection of the two blades, which is also the reason why some blades have empty grooves. You suggest that the mechanic widen the gap of the blade first, then pad the upper part of the upper blade with a thickness of about 0.3 mm, and pad the lower part of the lower blade with a thickness of about 0.3 mm, and then adjust the uniformity of the overall gap of the blade to meet the shearing needs of appropriate plate thickness. If the effect is a little worse, you won't pinch the blade if you pad it again. If possible, it is best to disassemble it and rework it.