U-bolts are designed to be inserted through holes that have already been drilled or punched. Perfect for used as framing fasteners and anchors for foundations and roofs, pipe and conduit holders and bolts for motor and engine shaft components. U-shaped bolts are typically used to support pipework or to attach a part to a pole, beam or wall. 18.8 stainless steel has good outdoor and chemical resistance and may be mildly magnetic.