Author Topic: Actual rating of pintle pattern on rear frame - anyone know?  (Read 742 times)


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I know it's easy to answer "well it's pretty strong..."  but I'm curious if anyone knows the actual pull rating for the pintle pattern.

I have a pretty stout recovery shackle but it's only as strong as its weakest link;  that would demolish anything in its path if the bolts didn't hold.

In this case I have M12-1.25 class 10.9 bolts (not OEM, they are longer to give full thread engagement with the thicker pintle plate)  which have a proof tensile of 17175lb (76400 Newtons) and I think it's acceptable to estimate that with four of those bolts,  maybe they aren't 4x that strong together (because it's unlikely I'd be loading four identically)  but estimating 2x seems conservatively safe. 

Now we're in guessing territory.      There's also the matter of the nuts into which those bolts thread - the bolts are class 10.9 but the nuts may be class 5.6 for all I know.   M12-1.25  threads in class 5.6 are rated to a minimum of 10363lb (46100 Newtons) .   If they're class 4.6 the minimum strength is rated 8273lb (36800 Newtons)

Would be cool to know if a credentialed engineer somewhere has signed off on a real number..

And, while we're on the topic does anyone know the rating of the factory tow loop?