E-4340 Aircraft Alloy

Alloy E 4340 steel is a medium carbon, low alloy steel know for its toughness and strength. It is often used in deep-hardening construction steel. 4340 has good ductility in the annealed condition that permits it to be bent or formed. The high fatigue strength makes E4340 suitable for highly stress parts since it maintains it’s strength and hardness at elevated temperatures.