Loosen frozen metal parts the professional way with Kroil original penetrant in liquid and aerosol (formerly AeroKroil) formulas. Discover why this is the best penetrating oil to loosen bolts in various applications. When it comes to freeing corroded items in tough spaces, nothing rivals the powerful, industry-proven Kroil penetrating oil. Trusted by professionals and experienced DIYers alike since 1939, Kroil: Quickly loosens rusted nuts and bolts Frees frozen shafts, pulleys, and more Penetrates the smallest openings, threads, or crevices Corrosion meets its match with Kroil, as it: Removes and prevents rust Cleans and lubricates Displaces moisture New! NSF Nonfood Compounds Program listed, category code: H2 Registration #165745. Key Features: Attacks Corrosion: Frees bolts, fasteners, and other mechanical components. Removes Rust and Carbon Deposits: Will not attack or damage metal. Penetrates Faster: Works quicker and deeper than similar products. Works Everywhere: Perfect for any corroded threads or tight parts. Simplifies Repairs: Makes the toughest maintenance jobs easier, faster, and safer. Penetrates Deeper: Reaches the smallest spaces, threads, and openings.