U-Bolts have primarily been used to support pipework, pipes through which fluids and gasses pass. As such, U-bolts were measured using pipe-work engineering speak. A U-bolt would be described by the size of pipe it was supporting. For example, a 40 Nominal Bore U-bolt would be asked for by pipe work engineers, and only they would know what that meant. In reality, the 40 nominal bore part bears little resemblance to the size and dimensions of the U-bolt. The nominal bore of a pipe is actually a measurement of the inside diameter of the pipe. Engineers are interested in this because they design a pipe by the amount of fluid / gas it can transport.
Standards : ASTM / ASME / BS / DIN / BS EN ISO
Size : 1/4" to 7/8"
Length : 3 mm to 200 mm
Threads : UNC, 8UN, UNF, Metric Coarse & Fine Series.
Material & Grades
Stainless Steel U Bolts :
AISI 302, 304, 304L,316, 316L, 310, 317, 317L, 321, 347, 410, 420,904L etc.
Duplex & Super Duplex Steel U Bolts :
UNS No. S31803, UNS No. S 32205, UNS No. S 31254, UNS No. S 31550, UNS No. S 32750, and UNS No. S 32760
Nickel Alloy U Bolts :
UNS 2200 ( NICKEL 200 ), UNS 2201 (NICKEL 201 ), UNS 4400 (MONEL 400 ), UNS 8020 ( ALLOY 20 / 20 CB 3, UNS 8825 INCONEL (825), UNS 6600 (INCONEL 600 ), UNS 6601 ( INCONEL 601 ), UNS 6625 (INCONEL 625), UNS 10276 ( HASTELLOY C 276 )