Standard U-bolts (or round U-bolts) attach pipes or round steel bars to wood or steel posts. They may also hang pipe from walls or ceilings or may be embedded in concrete as anchor bolts. They are stronger than routing clamps and hangers. U-bolts are fastened with nuts for a tight connection. Black oxide-coated U-bolts are corrosion resistant in dry environments. Zinc-plated U-bolts are corrosion resistant in wet environments. Hot dipped galvanized steel U-bolts are corrosion resistant, stringer than regular steel and are resistant to abrasion. These U-bolts are also available in lightweight aluminum or naturally corrosion-resistant 304 or 316 stainless steel.