Aviation grade bolts

Aircraft quality bolts are made from alloy steel, stainless or corrosion resistant steel, aluminum alloys and titanium

Within our industry the first two are the most common

Aircraft bolts will always have a marking on their head

If you see no markings at all on the head of a bolt, do not use it

Aircraft-grade bolts are designed to meet standardized specifications of strength and size

These specs are determined by three standards that have evolved over time: AN (for Army-Navy), MS (Military Standard), and NAS (National Aerospace Standards)

A given bolt should only be replaced with its identical

The most common types of aircraft bolts are hexhead, clevis, and NAS, which are distinguished mainly by their head designs

Hexhead bolts, naturally, feature a hexagonal head, whereas clevis bolts have a rounded flat-slot head, and NAS bolts, which meet a higher standard of tensile strength, often have a countersunk head