- The bolt is a joining element composed of a hexagonal head and a threaded rod. The bolt connects two parts using a supplied nut, which must match the thread size. You must use the correct size hex key to tighten and loosen the bolt to prevent rotation of the nut and avoid damaging the head. - Our bolts are fully threaded for very quick and easy assembly that always provides the expected and permanent result. - Our screw with nut is mainly used for: machinery, furniture, car and motorcycle repairs, DIY inventions, environmental protection equipment, medical equipment, communication equipment, electrical installations, electronic products, food machinery, petrochemicals, ship assembly, pump and valve pipes, construction curtain walls, and so on for fixing, splicing, connecting, assembling, tightening, and fastening.