Hex Nut with a Nylon-Filled Collar at its Back End; When a Screw Reaches the Collar the Threads and Nylon Form a Tight, Frictional Fit, Restricting Movement of the Screw When it is Subjected to Vibration; Able to be Reused More Times than a Two-Way Reversible Nut; Designed to be Used with Like-Material Machine Screws and Bolts

Specifications:

Type: Nylon-Filled Collar
Nominal Diameter: 1/2 Inch
TPI: 13
Thickness: 0.609 Inch
Width Across Flat: 0.752 Inch
Material: Steel
Finish: Zinc Plated