Parallel screws are cylindrical parts with threads, usually made of metal. There is a series of threads on the screw that can match the threads of the sleeve. One end of a screw usually has a nut, which is used to rotate the screw.
A sleeve is a cylindrical part with internal threads, usually made of metal. The internal thread of the sleeve matches the external thread of the screw. One end of the sleeve usually has an opening that allows the screw to be inserted and rotated..
screw
Specification 130/28
inlet zone
Specification 130/28
barrel
Specification 130/…