Dayton Superior B27 Nut Washer combines the advantages of a washer and nut into a one-piece ductile iron unit. The nut washer is equipped with nailing holes to secure them to the formwork and are designed to spread the forming loads over the wood forming members. The B27 has coil thread in the 1/2" and 3/4" diameter sizes and can be used with all appropriate coil threaded device.