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Kroil Original Penetrant. Best Penetrating Oil.

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.

Best Penetrating Oil Used by the Pros

When it comes to freeing corroded items in tough spaces, nothing rivals powerful, industry-proven Kroil penetrating oil. Used and trusted by pros and experienced DIYers alike since 1939, Kroil quickly loosens rusted nuts and bolts, frees frozen shafts, pulleys, and more. No space is too tight to reach, thanks to Kroil’s ability to penetrate the smallest opening, thread or crevice. Corrosion meets its match, as Kroil removes and prevents rust, cleans and lubricates, and displaces moisture.

Available In

Drip: 8oz
Aerosol: 10oz, 13oz, 16.5oz
Liquid: 1gal, 5gal, 55gal

Attacks Corrosion

Frees bolts, fasteners and other mechanical components

Removes Rust and Carbon Deposits

Will not attack or damage metal

Penetrates Faster

Penetrates quicker and deeper than similar products

Works Everywhere

Use on any corroded threads or tight parts

Simplifies Repairs

Makes the toughest maintenance jobs easier, faster and safer to execute

Penetrates Deeper

Penetrates the smallest spaces, threads and openings
  • Agriculture
  • Automotive
  • Aviation
  • Construction
  • Electrical
  • Facilities Maintenance
  • Factories
  • Firearms
  • First Responders
  • HVAC
  • Industrial
  • Infrastructure
  • Lumber
  • Manufacturing
  • Maritime
  • Mechanical
  • Metal Fabrication
  • Military
  • Mining
  • Oil & Gas
  • Plumbing
  • Utilities
  • Transportation
  • Agricultural equipment
  • Automobiles
  • Bearings and bearing mounts
  • Boats and marine equipment
  • Bushings
  • Castors
  • Chains and track pins
  • Construction equipment
  • Conveyors
  • Corroded fasteners
  • Drilling equipment
  • Engines and engine parts
  • Equipment disassembly
  • Firearms
  • Frozen gears and cogs
  • Frozen nuts and bolts
  • Gearboxes
  • Heat exchangers
  • Hinges and pins
  • Hitches
  • Locks
  • Lugs and lug nuts
  • Pillow blocks
  • Piping
  • Plumbing fixtures
  • Printing presses
  • Pulleys
  • Pumps
  • Rivet guns
  • Saws
  • Screws
  • Shafts
  • Sliding mechanisms
  • Sporting equipment
  • Turbines
  • Valves
  • Washers
  • Winches and cranes

Maintenance Tips

Hacked Off

Use Kroil Original Penetrant on saw blades and teeth to keep equipment from jamming, and ensure smooth, clean cuts. Also works well with honing and lathe equipment.

The Sporting Life

Use Kroil products to clean and eliminate rust from hunting equipment, fishing rods, boat parts, car racks and other equipment that may sit for long periods and/or be exposed to the elements.


“Kroil has been the most impressive penetrating oil…I would never not have Kroil on hand for the toughest jobs.”

Machinery Maintenance Supervisor, Petroleum Refining Company

“I don’t really care how much the stuff costs…a couple of squirts of Kroil just doesn’t cost that much compared to the cost of the job.”

Maintenance Manager, Power Company

“Kroil is the penetrating oil that I swear by. If you use it on a seized part, it is guaranteed to come apart.”

VP of Maintenance and BD, Aviation Maintenance Company


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