The slip shaft is also known as differential shaft and winding shaft. The slip shaft is an upgraded version of the air expansion shaft. The precision, difficulty and requirements of the product manufacturing have been improved by several grades, so the products rolled up by the slip shaft are also very perfect. It is mainly used for winding of slitting machine and unwinding in special occasions. The purpose is to use the principle of slip ring on slip shaft to make multiple coils of material on the shaft and keep stable tension for winding and unwinding.