Square U-Bolt Grade 10.9, Boat Trailer U-Bolts 1/2 D X 3 1/16 W X 5, 4 Packs This set includes 4 heavy-duty u-bolts, 8 flat washers, 8 lock nuts, and 8 lock washers, all crafted with the robust Dacromet coating for enhanced durability. Designed to fit 3x3 inch square beams and shafts perfectly, these u-bolts boast ideal dimensions of 1/2 inch diameter, 3 1/16 inches width, and 5 5/16 inches length, with a 2-1/2 inch thread length. Constructed using the superior Dacromet coating, these heavy-duty u-bolts can withstand challenging conditions, including exposure to rain, humidity, and corrosive environments. Installing these heavy-duty u-bolts is a breeze. These heavy-duty u-bolts are suitable for a wide range of applications, including connecting rectangular wood and metal objects such as cars, sailboat trailers, pipes, tubes, and industrial equipment.