Questions about O-Ring
What does federal supply class 5331 cover?
Federal supply class 5331 covers O-rings, the round-section sealing rings used in grooves to seal fluid and gas connections. Every item filed here is an O-ring.
How is a part in federal supply class 5331 identified?
Because every item in the class has the same item name, the NSN is what tells one O-ring from another. Each NSN record carries the characteristics on file for that exact ring and the part numbers cross-referenced to it, so a buyer can work from an MS or AS number, a manufacturer number, or a drawing callout. Each item in the class has its own National Stock Number (NSN) record, listed above.