Hard-to-Find Fastener 014973285050 Fine Nylon Insert Lock Nuts, 9/16-18, Piece-25 Diameter: 9/16-Inch Material: Steel Finish: Zinc Driver Type: 7/8 Wrench Thread Type: 18 (Fine) Diameter: 9/16" Material: Steel Finish: Zinc Driver Type: 7/8 Wrench Thread Type: 18 (Fine)