Brass reducer for reducing the size of internal threads. The reducer has a 6 or 8 point and is easily processed with an open-end wrench. Simply screw the brass reducer into the internal thread to be reduced. The threads are BSP pipe threads, which are commonly used in water technology. The external thread has a conical (tapering) shape, while the internal thread is parallel. The brass reducer, like all threaded brass fittings, can be used for both hot and cold water pipes.