BOLT, MACHINE - DOUBLE HEXAGON EXTENDED WASHER HEAD, CLOSE TOLERANCE SHANK, AMS4967 (UNS R56400), 160 KSI, .2500-28 UNJF-3A

This document establishes comprehensive technical requirements for a specific class of mechanical fasteners, namely machine bolts featuring a double hexagon extended pad head. Designed for high-strength applications, the specifications cover critical dimensions and dimensional tolerances for a threaded shaft with a tensile strength rating of 160 ksi. The standard defines precise geometric parameters for the thread form, designated as UNJF-3A, ensuring interchangeability and functional reliability within demanding engineering environments. It outlines the necessary manufacturing controls to achieve the required fit and finish, focusing on the thread pitch and major diameter specifications for the specified series. Material composition and heat treatment processes are governed to meet the stated strength criteria, ensuring the component performs consistently under high load conditions. The guidelines provided herein facilitate the production of uniform fasteners that meet rigorous quality benchmarks for aerospace and industrial machinery sectors. Adherence to these specifications guarantees that the manufactured parts maintain their structural integrity and dimensional accuracy throughout their operational lifecycle, supporting the broader goals of mechanical system reliability and safety.