U-Bolts Round U-Bolts ROUND U-Bolts Grade 8 Round U-Bolts Measure the diameter of the rod and click on the link below to purchase the appropriate Grade 8 Round u-bolts we stock. Each kit includes two u-bolts, washers and nuts. Round - 5/8" U-Bolt Round - 3/4" U-Bolt Round - 7/8" U-Bolt Round - 1" and larger U-Bolts