Gr 5 USS Bolts Hex Hd C/S 3/4"x4 1/2"Sold in sets of 20 Have a larger pitch (fewer threads per axial distance) compared to fine threads. Are specified for most applications unless there is an overriding reason to use a fine threaded bolt. Are beneficial because they are less likely to cross thread, more tolerant in adverse conditions and facilitate quick assembly. Are used when threaded into aluminum or cast iron because the finer threads tend to strip more easily in these materials. Are