Threaded concentric reducers are cone-shaped pipe fittings that have grooves and internal threads for connection. They reduce the size of the pipeline in a symmetrical and concentric manner while keeping the centerlines of the two pipes aligned. This product achieves mechanical coupling by using a set of grooves at the ends of the pipes and fittings. Typically, one end is grooved using a specialized tool, and then the joint is clamped onto the groove using bolts or a similar mechanism. The other end is threaded.