Bests & Worsts Reviews from Amazon

If you are one of those who solves every problem with crescent wrench, pliers, hammer, duct tape, portable drill, and take great pride in that behavior, then ignore this review. For those who do things the right way... The bolt heads are 18 mm. The nuts are 11/16". 17 mm will fit the nut but not if your wrench or socket has tight tolerances. You read correctly, THE BOLT HEAD IS A DIFFERENT SIZE THAN THE NUT. The only size that fits the bolt head properly is 18 mm, 3/4" is extremely sloppy and completely unusable, 11/16" will not fit at all. The bolts supplied are 4 1/2" (114mm) long with 2 1/2" (64mm) threaded. MOUNTING DATA A 4x4 bolt pattern 12 inch trailer wheel hangs 4 inches below the lowest point of the main mount bracket plate. The same as saying a 12 inch wheel will hang 4 inches below the trailer frame it is mounted on. Even though the mount angles upward, the tire itself hangs below. The picture provided on amazon hides that detail completely. (carefully employs parallax error to deceive) MAKE NOTE: A 12 inch tire will hang 4 inches below the frame IF.... the bracket is mounted at its highest point. A 12 inch tire "could" hang up to 7 inches below the frame. Therefore at best.... 4 inches below the frame. (larger tire hangs lower obviously) Best idea is as others have said. By some corrosion resistant grade 5 or grade 8 fastener hardware that fits your frame. This fastener hardware is truly junk and will corrode. The size is 7/16" or 11 mm if you prefer metric. Then.... the fasteners won't rust and the bolt head size will equal the nut size as usual and typical. Now the good news. For the price this is an excellent buy and works fine if you fix the hardware.