U-bolts are bolts bent in the shape of a "U" with machine threads on both ends that nuts can be threaded onto in order to fasten the u-bolt. Since u-bolts have primarily been used to support and secure pipe, u-bolts sizes are called out by the size of pipe. In addition to pipe, u-bolts have a wide range of uses such as securing tubing, roundbar, wood or steel posts, and can be embedded into concrete as anchor bolts. U-bolts are designed to be inserted into pre-drilled or punched holes. Made from austenitic 304 stainless steel. Stainless steel fasteners are commonly used in applications that require general atmospheric corrosion resistance, such as chemical and food processing equipment. Stainless steel has a higher corrosion resistance than carbon steel.