These brand new U-bolts are 100% made in Australia and are made from 304 stainless steel. 316 Stainless washers & Nyloc nuts included. These were custom made to hold fishing rod holders to 2 inch bull bars, but their small diameter will suit many other uses. 
 
These bolts will fit  ø53 maximum round bars and are diameter 6mm with M6 threads. 
 
Set includes : 2x U-bolts, 4x washers, & 4x nuts.