Tool with internally threaded sleeve and screw with hexagonal head is used for screwing in stiff screw or stud and screw has left-hand thread

摘要

The nut (4) has a normal hexagonal head and a shaft with a left-hand male thread. It screws into the upper part (2) of a sleeve (1) with a left-hand female thread. The lower part (3) of the sleeve has a right-hand female thread engaging on a stud with a right-hand male thread. A projection (5) on the bottom of the screw engages on the flat top of the stud.