The 300M alloy is similar to 4340 steel. It contains vanadium and high silicon content.
300M provides toughness and high strength with its high carbon content. .
In heavy industry, it is used in transmission parts, gears, shafts, as well as in defense industry, aviation, and landing gears. As a rocket motor casing.
AMS 6257 Bars / Forgings AMS 6417 Vac Melt Bars / tubes AMS 6419 Bars / tubes MIL-S-8844 Cl3, MIL-S-83135 ASTM A604 S155, BS 2S149