How To Choose The Correct Leaf Spring U-Bolt Diameter Size On A Trailer Axle

Updated 12/20/2010 | Published 12/18/2010

Question:

do you have these in the 1/2 diameter ,y ubolts or 1/2 would 9/16 be better or to small in strength

asked by: Irvin R

Expert Reply:

You will want to choose the diameter size of U-Bolts you need by the axle type (round, square) and the axle diameter. The Redline 2 Inch Square Trailer U-Bolt, part # SP01-160, you have referenced is for a 2 inch square axle. It is a 9/16 inch diameter bolt.

The 9/16 inch diameter U-Bolts are used on 1-3/4 inch and 2 inch square axles, 2-1/2 inch round axles, 3 inch round axles, and 3-1/2 inch round axles. I am including a link to a page of the available 9/16 inch diameter U-Bolts.

The smaller 1/2 inch diameter U-Bolts are used on 1-1/2 inch square axles, 2-3/8 inch round axles, and 3 inch round axles. I am including a link to the page of the available 1/2 inch diameter U-Bolts.

You will also want to match up the correct U-Bolt plate with the U-Bolt width and diameter.

I am including a link to a FAQ page on trailer suspension that will have a section on U-Bolts and U-Bolt plates.

expert reply by: Jeff D