Sprung Axle Torque Specifications
Axle size Axle Capacity Maximum ft.-lb.
U-Bolts 2k 25 ft. lb.
3.5k w/1/2" 50 ft. lb.
5.2k 65 ft. lb.
6-8k 90 ft. lb.
From page 13 of
Lippert Trailer Axle Operation and Service Manual
Oops! Info all runs together. Can't figure out how to space the info into columns. But you can see it on the link.