Abstract: Axially extending lobes extend radially from an internally threaded nut and form axial troughs that receive a respective axial cone mounted in the socket of a driver, the cones being rotatably driven against the lobes to apply a threading torque to the nut. At a predetermined torque, an axial outer radial end portion of the material forming the lobe is plastically deformed, but not sheared off, thereby allowing the socket to rotate and the cones to advance against the next respective lobe. The deformed lobe indicates to the user that the nut was properly torqued and the deformed material does not shear off thereby indicating that the nut had not been tampered with. To permit relaxation, a second torquing could be done at a later time.

Abstract: Axially extending lobes extend radially from an internally threaded nut and form axial troughs that receive a respective axial cone mounted in the socket of a driver, the cones being rotatably driven against the lobes to apply a threading torque to the nut. At a predetermined torque, an axial outer radial end portion of the material forming the lobe is plastically deformed, but not sheared off, thereby allowing the socket to rotate and the cones to advance against the next respective lobe. The deformed lobe indicates to the user that the nut was properly torqued and the deformed material does not shear off thereby indicating that the nut had not been tampered with. To permit relaxation, a second torquing could be done at a later time.

Abstract: The present invention relates to a fastening system comprising a nut with a locking threadform and a nut driving system which visually marks the locking nut when the proper torque is reached. The locking nut with a locking threadform has been designed so that the major diameter thread of a typical bolt will engage a wedge ramp portion of the nut threadform thereby resisting unintentional loosening. The nut driving system of the present invention comprises a wrench socket wherein the socket contains a ball set; when the socket is used to tighten the locking nut, it visually marks the nut head when the proper torque is reached.