Abstract: A universal compression nut fits on the threaded shaft of bolts, screws, studs and the like of different diameters and thread pitches. It slides into place without turning. It has two mating screw members that fit together and screw one into the other. These members have a central bore to receive the screw shaft. When the two members are screwed together movable inserts are forced by one member along sloping surfaces in the second member. This forces the inserts in against the threaded shaft. The inserts are soft enough that the threads on the shaft embed into the inserts forming matching threads. The nut now is rotated to apply tension to the threaded shaft.