Permatex 80631 Thread Sealant with PTFE, 1 oz. , White

What can I say....Permatex is a leader in thread sealant. Works great and used on John Deere mower oil filter change over install. Always a little messy but you get confidence in the finished job.

This stuff is great. Sealed a leak on a power steering fitting!

I absolutely love this stuff. I’ve used this Permatex PTFE thread sealant on two complete vehicle engine builds, and I’m only about halfway through the bottle, which says a lot about both coverage and value. A little goes a long way, and it applies smoothly without making a mess. I used it on cylinder head studs, intake fittings, transmission line fittings, oil cooler fittings, and several other threaded connections exposed to oil, coolant, and transmission fluid. In every case, it sealed exactly as intended—no seepage, no weeping, and no loosening after heat cycles. What I like most is that it seals while still allowing proper torque, unlike some sealants that either over-lubricate or harden too much. It’s held up against coolant, engine oil, and ATF with zero issues. Threads stayed clean, fittings went in smoothly, and nothing backed out during assembly or operation. This has become my go-to thread sealant for engine and drivetrain work. Reliable, efficient, and long-lasting—one bottle easily handles multiple builds. I wouldn’t hesitate to use it again on future projects.

I didn’t know this was a thing. I spoke to a mechanic and he uses it instead of the tape. I ordered a jar for myself. It works really well. My only complaint is it tends to leave a string from the pipe when it’s applied. Don’t use it in a place you’re worried about getting dirty. If I had to do it again I’d but it in a squeeze tube like the mechanic.

It's nice and works very well, but it's a little thick and because of that not always easy to apply.

Will definitely be buying more.

My 5-stars is for the product itself. Shipping wise.... half of them were opened in the box during transit. One completely emptied inside the box, another halfway, and the other two were trickling out. I got 8, four were fine, four were not. The price is not bad for these size bottles, so I'll likely order again.... just cross your fingers it makes it to you without too much loss. The caps on these bottles come off with about half a turn, since they're so short, it's a single thread keeping the tops on so if you get a few at a time, they will likely shake around and uncap each other. Hopefully whoever packs the products for shipping, keeps them in a more confined box, there was some decent room for all my bottles to move around in which is likely the cause of my mess.

Used for head studs.