What is the diameter and length of an AN8-12 bolt?

• A. 1/2 inch in diameter, 1 1/4 inch in length
• B. 1/2 inch in diameter, 1 inch in length
• C. 5/16 inch in diameter, 1 1/4 inch in length
• D. 3/4 inch in diameter, 1 1/2 inch in length

Answer: (A)

In aviation fasteners, the designation after AN tells you the diameter, and the trailing number refers to the length from a standard chart. The diameter part, AN8, means 8 sixteenths of an inch, which is 1/2 inch. The dash-number corresponds to the length listed in the standard AN bolt tables; for AN8-12, that length is 1 1/4 inches. So an AN8-12 bolt is 1/2 inch in diameter and 1 1/4 inches long. The other options don’t match the established AN bolt sizing: they would imply a different diameter or a different length for an AN8-12 bolt.