Standard U-Bolt, Standard U-Bolt, 304 Stainless Steel, Finish Plain, Thread Size 1/4 In.-20, Thread Length 2 1/2 in, Inside Length 3 7/16 in, Inside Width 1 3/8 in, Pipe Size (In.) 1 in, Characteristics Has Coarse Rolled Threads, for Steel or Wrought Iron Pipe Sizes, Includes 4 Hex Nuts