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does anyone know how hard the aftermarket ubolts are. i have to replace mine. i can get grade 5 but i didnt know if i should look for grade8. will the grade 5 be ok i know grade 8 is harder and that would be better but will grade 5 be ok
54 chevy 1.5 ton

thanks

In my opinion grade 5 should be fine. Grade 8 is harder, but also more brittle. 50 years ago lots of u bolts were made in small town shops out of plain old cold roll and I never heard of one failing.

54 big truck,

I had the same question myself. I went to the local blacksmith/spring shop where they make them to order...I asked what material they used. They told me they use 4140. I made my own out of 4140. I don't actually know what a stock u-bolt is made from but Crenwelge might be correct.

Stuart

check out the trailer places and parts houses. Most have something you can use hanging on a shelf. Even Notthern Tool and few other places.

I think most spring shops make ubolts from grade 5 steel. It will stretch before it breaks. Grade 8 is too brittle. About that 4140 steel - isn't that Chromium -Molyb denum? That's strong stuff they make tubular chassis from.

Some years ago when we were still running spring ride Hutch suspension on our trailers they went from a 7/8 to a 3/4" high tensile U bolt for weight savings. We speced our trailers with single leaf springs which broke quite often, and we always used new u-bolts. That left lots of u-bolts laying around. We have bent them in all kinds of shapes, the high tensile included, in a hydraulic press to make some special hook or something and never had one to break in the press. This leads me to believe they were no harder then 5. Grade 8 won't take much of a bend and it snaps like glass.

I just went to a truck spring shop. They made them right there. They had stock lengths of material, and a hydraulic press. Violia. It wasn't expensive either.

I don't know how one would make a U bolt out of stock. The stock bolts that the spring shops bend into shape have a shank that has a smaller diameter than the threaded portion. This is to allow the non threaded portion to stretch before the threaded portion.

We still have a lot of NOS U Bolts that were specific to an application of trucks and trailers that we have retired long ago. The old ones have the shank the same size as the threads, and these were OEM replacements for Dayton, Reyco, etc. suspensions. The old Fruehauf F2 suspension also used u bolts with the shank the same size as the thread.