I agree, get the "blue wrench" out and cut 'em. U bolt threads are cold rolled, not cut. The principle that they cannot be reused is because the torque will never be close to the same to achieve the same clamping force. The underlying idea behind the clamping force, is that any loosening of the spring pack usually leads to broken leaves.

Retorques should be performed after several hundred miles of good hard use. It's just good practice to follow generally and believe people should at minimum know and understand procedures before they decide to deviate from them.

 

I agree with everything else you said (except the torch part obviously) but what the heck is that supposed to mean?

(and rolled threads supposedly perform better than cut ones anyway)

 

been a few years now of course,but i wanna say somewhere between 40 to 60 bucks.
you say compare it to the cost of used junkyard u-bolts,but my thinking is;
compare it to cost of what could happen in the event of u-bolt failure/loosened nuts.
comparatively to what could go wrong (death to yourself or others,or serious injury) new u-bolts (once in a blue moon when needed) is actually pretty cheap insurance.
if we were talking about something you would replace more than once or twice in 20 years........well maybe then this discussion could be worth more of my time.since we're not,im afraid this is all im devoting to this one.
whatever you decide to do in the future,be safe!

 

I say it's absurd to compare it to the potential cost of an accident. Equipment failures are just a small slice of accidents and of equipment failures there's tons more common than U-bolts. Clearly we assess the situation differently. If it helps you sleep at night then buy all the U bolts you want. We both have better things to argue about.

 

Just look at it as "best practices", this is what the spring manufacturers recommend, it's not going to break the bank, I hate reusing rusty hardware anyway, and at least new leaf springs are fairly expensive - don't want them to break. They will look rusty soon enough I guess.

From a technical standpoint the threads are deformed somewhat upon tightening to their torque spec, this is part of what keeps them from loosening. If you think about it, there's no cotter pin or locknut or anything used on what is a pretty important set of nads.

They stretch somewhat as well. It's my understanding to achieve the same clamping force upon reuse, requires a much higher torque value than recommended and may exceed their yield strength. Will they fail?

Probably not. But that's not how things are supposed to be done. To me it's important to know how it's supposed to be done, and why before I do things different.