8-18 x 3/4 Combination(Slot/Phil) Pan Self Drill Screw Full Thread Zinc/Bake WN188 and the jam nut design

and the jam nut design helps to prevent loosening due to vibration

These screws are available in a variety of lengths and can be used in a variety of applications

5 DIN6797A Metric External Tooth Lock Washer Zinc And Bake is a high-quality washer designed to prevent loosening of nuts and bolts due to vibration or other factors

* Size: 5/16-18 x 2 1/2

The screw is 2-1/2" long and has a diameter of 5/16"

8-18 x 3/4 Combination(Slot/Phil) Pan Self Drill Screw Full Thread Zinc/Bake WN188 and the jam nut designThese screws are designed for use in a variety of applications, including metal to metal, metal to wood, and wood to wood. They are self drilling, which means they can be driven into metal without the need for a pilot hole. The pan head provides a flush finish, and the combination slot Phillips drive allows for easy installation with either a screwdriver or a drill. The zinc bake coating provides corrosion resistance, making them ideal for outdoor use.