It is a piece with a central hole, which has a thread, which is used to attach to a screw in a fixed or sliding way. The nut allows to fasten and fix removable element joints, designed for use in high pressure and/or high temperature service, made of medium carbon steel, tempered, they are approximately 10% wider and taller than standard hex nuts and they distribute the load over a large area, have a load resistance of 175,000 psi and are identified with the writing 2H.