5 pcs M6pcs 20mm Thread Wing Bolt Butterfly Screw 1 set Nylon Lock Nut Assortment KitMade of 304 stainless steel, which have high hardness and wont be decompatible withmed.Designed with nylon insert making it capable enough to replace common lock washers and hold bolts more firmly.170 pieces nylon insert lock nuts are packed in a sturdy plastic box, which allows you organize the lock nuts according to size neatly and conveniently.widely used in automobile, construction machinery, shipbuilding, etc.Color: SilverWing Butterfly Screw:Overall Size: 35 x 25 x 10mm/1.36 x 1 x 0.4 inch (L * W * T)Thread Size: M6 x 20mm/0.24 x 0.8 inch (D * L)Thread Pitch: 1mmMade of 304 Stainless Steel in silver tone, the thread pitch is 1mm, Features two large stainless steel wings.You can tighten these a little better than the regular oval head screws with the extra wide wings.Used widely in the home and office appliance, communication equipments, ship assembly and other machinery industry.Material: 304 St