fastener questions, split lock washer, nylock

[Scott Douglas]

Are you sure it's not because it out gasses too much, Hugh?

[cashflyer]

Are you sure it's not because we are afraid of alien civilizations procuring our Loctite technology, Hugh?

[Hugh R]

Pretty sure its the deformation of the light weight bolts that they use. Titanium I believe. I have a "used" bolt (pretty big, like 2" long and 1/2" diameter with a weird looking head for torquing, that is serial numbered and made of Ti, it has some blue locktite blob on the side of it. I know once put on and tightened, if loosened, they throw it in the scrap pile.

[red-beard]

Originally Posted by jyl

Little tube of Locktite Blue (the removable sort) will make most of this moot.

Nylock nuts are re-usable for common, non-critical applications. Even after being re-used, they still have enough resistance to rotation that they won't easily vibrate loose. But for anything where it really matters, I would not re-use them.

This

[dad911]

Rust. After spending three hours this afternoon grinding the heads off of bolts to an access panel, I've decided rust is the best locking mechanism for nuts and bolts.

[john70t]

dad911:
$30 angle grinder from harborfright will get er done.
First try hammering on face, impact and lube back and forth, heat, and torquing until the bolts snap in two.

[sammyg2]

Originally Posted by dad911

Rust. After spending three hours this afternoon grinding the heads off of bolts to an access panel, I've decided rust is the best locking mechanism for nuts and bolts.

There might be better stuff out there but I haven't found it:

[zakthor]

The bolt for bike rack is >1/2", too big to tighten until stretch.

The joint looks like a hack, not something you'd find on the space shuttle. In this case the bolt is tightened, it holds the far side of the rack against the hitch. Holes are oversize so loose fit, probably there is motion too.

Ok, so what is a general rule as to when a split lock washer is reasonable?

I can guess: "might be reasonable for a loose hack fest" but hoping for something more formal. I don't even know how to characterize this situation.