Interrupted screw

An interrupted screw or interrupted thread is a mechanical device typically used in the breech of artillery guns. It is believed to have been invented in 1845.

The system has also been used to close other devices, including the joint between helmet (bonnet) and breastplate (corselet) of standard diving suit helmets, and the locks of diving chambers. Interrupted thread mounting is also used for large instrumentation lenses for high-speed cameras such as the Photo-Sonics 10B.