Product Info Catalog Hardware Builders Hardware Connection & Wire Goods U Bolt, #522, Zinc, 5/16 x 1-3/4 x 3-In. U Bolt, #522, Zinc, 5/16 x 1-3/4 x 3-In. Request a Quote UPC: 38613125957 SKU: 661561 Model Number: N222-141 5/16" x 1-3/4" x 3", #522 zinc u-bolt.