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What qualifies as ordnance steel.
gunphreak
Member Posts: 1,791 ✭✭✭✭✭
I have an AR-15 disconnector that is beginning to rust. I thought these things were made out of an alloy steel that resists rust.
Anyway, what are they made out of???
Anyway, what are they made out of???
Comments
I don't know what steel was used on your particular rifle because the type varies from manufactuer to manufacturer and from time to time, plus the government has spec'd steel on occassion which is designated WD for War Department.
The most common steel used in modern firearms (all types of parts) is chrome-moly steel. It is designated as 4140 which means it is a high carbon steel and can have a tensile strength up to 180,000 psi. It contains approximately 0.40% carbon, 0.8 to 1.1% chrome, 0.75 to 1.0% manganese, .15 to .25 molybdenum. 0.04% phosphorus, 0.04% sulfur, .2 to .35% silicon, and no nickel. The barrel of the rifle may be chrome lined or not. If it is it is only a thin layer about 0.0005 to 0.00075 inches thick.
So the long answer to your question is the disconnector on your AR-15 is probably made of an alloy steel (because plain steel is too soft) that is quite hard and tensile. But just because it is an alloy does not mean it won't rust. Even stainless steels which are labeled "rust resistant" will still rust and must be protected against corrosion. It would probably be a good idea to keep all the steel parts of the rifle wiped down and oiled to protect against corrosion.
Regards,
Heavyiron
The disconnector is older than any other part in my rifle, and was manufactured by Armalite. To my understanding, it may well be older than I am (33 years old).