Nuts

Used in combination with bolts for high shear and tensile strength fastening, aircraft nuts are typically made from steel or steel alloy with a corrosion resistant plating such as cadmium or zinc. In order to stand up to the high rate of vibration in aircraft operation, aviation-grade nuts must feature a locking device. The most common such devices are cotter pins, fiber inserts, lockwashers, and safety wires.

A variety of bolt styles meet a variety of purposes. Castle nuts are often used with shank or clevis bolts and are slotted to allow a cotter pin; they are generally used where shear strength is required. Self-locking nuts feature a fiber insert or, for use in high-temperature areas, a narrowing thread to optimize friction. Plain aircraft nuts utilize a lockwasher or a locknut to maintain position.

In addition to these most common types of aircraft nuts, a variety of other designs are available to meet specialized requirements.