A hollow hex plug BSPP‑M is a precision‑engineered pipe fitting designed to seal or close the end of a female BSPP‑threaded port or fitting while allowing internal access through its hollow center. It features male British Standard Pipe Parallel (BSPP‑M) threads and a hexagonal head for easy tightening or removal with a wrench. The hollow design allows for tasks such as pressure testing, venting, or temporary instrumentation connections without fully opening the system.
Hollow hex plugs are widely used in hydraulic, pneumatic, instrumentation, and fluid systems across industries including oil and gas, chemical processing, power generation, and industrial manufacturing. When installed with an appropriate O‑ring or bonded washer, BSPP threads provide a secure, leak‑resistant seal suitable for high-pressure applications.

