Spreader dowel for wooden suspended ceiling - has shaft nut for equally long spreader protruding unit end thread

摘要

The dowel plug has a spreader element fitting into a hole for splaying the parts of its slitted end sited in the concrete. The protruding retainer end is threaded for application of a tension-metering device and the further protruding spreader element and is a striking head, and also serves as limiting stop. The nut for screwing onto the thread is a shaft nut (14, 15) pref. of the oval countersunk type with peripheral screw slit. The thread (10') on the outside face of the dowel is at least as long as the nut.