Kroil Penetrating Oil with Silicone (Liquid-55 Gallon Drum-Single) | Penetrant for Rusted Bolts, Metal | Lubricant for Hinges, Chains, Moving Parts (SK551)

I was surprised at how great this product works. It loosened frozen screws and bolts faster than any item I tried before. Don't waste your time or money on any thing else.

Amazing product and works better than any other rust penetrant I have ever used. If you have a rusted on part don’t waste your time with other products. Expensive but worth every penny when when nothing else will work!!

Stuff just works LOL, all I can say.

I had a particular use in mind when I needed to remove a O2 sensor on a 28 year old pickup. Knowing that it was likely rusted and seized into place I wanted to ensure I gave myself the best chance or success without stripping the threads. I've used countless different penetrating oils over the past 50 years and spent a lot of time working on older machinery. I had heard some excellent testimonials for Kroil. I sprayed the sensor multiple times over a couple days to let it soak. When I put a wrench on it, I was amazed. After breaking it loose and turning it about 1/2 turn, I was able to remove it with my fingers the rest of the way. It was like it was installed a month ago. It's a little pricey, but if I continue to see this kind of results it will be my go-to. I've been pleased with how it has worked on other projects, but the O2 sensor was the biggest challenge.

It works. Great.

The best I've every used. The only reason I gave 4 star instead of 5 is the price - very expensive but you get what you pay for. I've been using this product for over ten years around the farm and job and it just cannot be beat for loosening corroded bolts and nuts. It definitely is "the oil that creeps". Follow instructions. It doesn't take a whole lot of it but if you have an un-breakable bolt/ nut just give this stuff time to do its magic and you'll be amazed at its effectiveness.

Pricey but the best there is in my experience

Works great! Used on rusted screws to loosen. Used on squeaky windmill and sticking wind spinners. I have used on other items as well and reach for this so much that I can't remember everything it has worked on.