Sulfur: 0.025% Max
Phosphorous: 0.025% Max
4340 AQ is typically bought to meet chemistry requirements rather than physical requirements. For that reason, physical properties are generally not provided unless requested prior to production. Any material can be sent to a third party after production to be tested for physical properties.
Typical uses for 4340 alloy include:
- Landing Gears
- Power Transmission Gears
4340 Cold Finish Aircraft Quality
Alro stocks 4340 AQ - a highly alloyed steel with high nickel and chromium content which assures deep hardening when oil quenched, with high strength characteristics throughout the section. Used for heavily stressed parts operating under strenuous conditions.