1.Nylon-insert lock nut, polymer-insert lock nut, or elastic stop nut, is a kind of locknut. 2.It is a nut with a nylon insert that resists turning. 3.The plastic insert is placed at the end of the nut, and its inner diameter (ID) is slightly smaller than the main diameter of the screw. 4.The insert elastically over the threads of the screw, but threads are not cut into the nylon. Specification:Material: Carbon SteelFinish: White zinc platedThread Size: M8Pitch: 1.25mmHex Width: 13mm / 0.51"Height: 8mm / 0.31"Package Content: 20 x Hex Lock Nuts
