CRC Knock'er Loose penetrates cracks, machine assemblies, frozen connections, and fittings with its freeze shock action to quickly dissolve rust, corrosion, grime, and grease. The 50-state compliant formula makes it easy to disassemble tools, automobile engines, plant machinery, and other equipment for routine maintenance. This industrial-grade penetrating solvent is NSF H2 registered for use in meat and poultry plants. It works effectively on various metal fittings, hinges, bushings, washers, lugs, nuts, bolts, metal joints, and couplings.