Product Info Catalog Hardware Builders Hardware Connection & Wire Goods U Bolt, #516, Zinc, 5/16 x 1-3/8 x 3-3/4-In. U Bolt, #516, Zinc, 5/16 x 1-3/8 x 3-3/4-In. Request a Quote UPC: 38613125902 SKU: 661553 Model Number: N222-133 5/16" x 1-3/8" x 3-3/4", #516 zinc u-bolt.