hreaded couplings are perhaps the most common and widely used in many industrial sectors from the hydraulics to wine production. They are distinguished by the type of thread (BSP or NPT) whose different norms are such that the helical pitch of the thread does not allow the possibility of cross-threading with each other. They can be made in various materials and used in many situations as low cost connection solutions.
They are available in PVC, PP, PE, Nylon, Bronze, Aluminium, Steel, various metallic alloys, cast iron, stainless steel, etc..
They are generally made of two parts, one with a Male external thread, and the other with a female nut with a matching internal thread which is screwed onto the male when fixing together the two fittings. There are so-called conical models for applications that do not allow the use of sophisticated seals between the male and female sections, the shape of the inside of the seal between the two is that the union is perfect thoughout. That said most of the time, however, these fittings have a flat bar between the male and the female, and in this case it is necessary to insert a rubber gasket of suitable quality to chemically resist the transported medium.