These RHR HD Multi Grip Rivets have superior strength and quality. Great for fastening, metals plastics, vinyls and more. Made with an 3/8″ aluminum head and steel mandrel, these rivets crimp nicely and hold well. The body of the rivet is 3/16″ in diameter and has a grip range of .187 – .437 or up to 3/8″ and has a max length of 5/8″. Backup washers are not necessary, but will add even more strength. Order in quantities of 250 or 500 (bagged).