The off-white nylon 6/6 hex bolt has an external hex drive and meets American Society for Testing and Materials ASTM D4066 and D6779 specifications. Nylon 6/6 provides resistance to abrasion, corrosion, and many chemicals and solvents. The material is a strong yet lightweight plastic and is nonconductive. Nylon 6/6 can either absorb or lose moisture, which may alter its dimensions and mechanical properties. The external hex drive has six flat sides that a wrench can grip to turn the screw from the side, enabling use when there is no space above the head for a driver.Cap screws and hex bolts are threaded fasteners with thick hex-shaped heads that can be used with threaded nuts or in areas with limited clearance above the tapped (threaded) hole. Cap screws have slightly different dimensions than hex bolts and have a washer face underneath their unflanged hex head to act as a large bearing surface against the mating material.
