12-11 x 1 1/2 Slot Hex Washer Self Piercing 5/16 Across Flats Full Thread Zinc Needle Point 1-1/2-6 They have a hexagonal shape

They have a hexagonal shape with two flats on opposite sides for easy tightening and loosening with a wrench

Its 1/4-20 thread size and 5-inch length provide a secure hold in wood

including:

This 1/4-20 x 1/2 Phillips pan machine screw is made of 410 stainless steel

12-11 x 1 1/2 Slot Hex Washer Self Piercing 5/16 Across Flats Full Thread Zinc Needle Point 1-1/2-6 They have a hexagonal shapeThese 12 11 x 1 1 2 Slot Hex Washer Self Piercing 5 16 Across Flats Full Thread Zinc Needle Point screws are designed for use in metal applications. They have a hex washer head with a 5 16" across flats and a slot drive. The screws are self piercing, which means they can be driven directly into metal without the need for a pilot hole. They have a full thread, which provides maximum holding power. The screws are made of zinc plated steel for corrosion