Threaded insert for plastics has sleeve with internal and external threads to receive expansion screw for slit along length

摘要

The threaded insert for a bore has a tubular body (4) with an outer face (6) carrying an external thread (12) and an inner face (10) with an inner thread (14). The body has a longitudinal slit (16) extending over part of its length, defining a cutting edge to aid screwing in of the insert. The inner thread extends for part of the length of the insert, leaving part (18) unthreaded, which expands when a screw is inserted due to the slit.