M4 x 0.7mm Nylon Insert Hex Lock Nuts 201 Stainless Steel 30 Pcs

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 major diameter of the screw. 4.The insert deforms elastically over the threads of the screw but threads are not cut into the nylon.