AN4H-26A Bolt Drilled Head

Hex head bolts for aerospace applications are manufactured from high-strength alloy steel, type 4037 or 8740 (type 8740 being the most common). These bolts are centerless ground and heat-treated for threading. Minimum tensile strength: 125,000 PSI. Cadmium plating conforms to QQ-P-416A, Type II, Class 3. Available with a shank drilled for a cotter pin or undrilled for a lock nut, and with or without a head drilled for a safety wire. For bolts with an undrilled shank, add the letter "A" after the part number. For bolts with a drilled head, add the letter "H" after the AN part number. See the illustrated examples. The length of AN aerospace bolts is measured from the underside of the head to the end of the shank. The unthreaded portion of the shank is the threaded area. Refer to the table for converting the length and/or grip area to the appropriate AN designation.