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