These Purlin Bolt assemblies feature a Flanged Hex Head bolt, a Flanged Hex nut which eliminates the need for any washers and makes it much quicker, easier and safer to instal than the traditional bolt, nut and two washer assemblies. They are specifically designed for fastening steel purlins to metal purlin cleats in steel framed sheds and buildings. They come as an assembled product with a bolt and nut attached for ease of handling.