1. A threaded nut, one side of which is dished to retain a grommet; used in forming a watertight pipe joint.
2. A locking nut on the shank of a pipe fitting, tap, or valve.
1. A threaded nut, one side of which is dished to retain a grommet; used in forming a watertight pipe joint.
2. A locking nut on the shank of a pipe fitting, tap, or valve.