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MS28778 — O-RING

✓ Government record, cited
— · ORING SEAL
PRODUCT OVERVIEW

MS28778: O-RING.

The O-RING is a the manufacturer industrial component. Key specifications include part_name_assigned_by_controlling_agency: PACKING, PREFORMED, STRAIGHT THREAD TUBE FITTING BOSS.. This part is cataloged in the U.S.

Government catalog under NSN 5331-01-490-6342, indicating validated use in U.S. government and defense logistics supply chains. Available through authorized enterprise resellers and TPM (Third Party Maintenance) channels.

Verify compatibility with your specific system configuration before ordering.

WHERE IT FITS
MS28778
NSN: 5331-01-490-6342
FSC: 5331 — O-ring
CAGE: 0U583 — SAE INTERNATIONAL DBA SAE INTERNATIONAL (USA)
SPECIFICATIONS
part_name_assigned_by_controlling_agencyPACKING, PREFORMED, STRAIGHT THREAD TUBE FITTING BOSS.
NSN5331-01-490-6342
COMPONENT DIAGRAM
O-RING / SEAL — MATERIAL DETERMINES APPLICATION ID: — CROSS-SECTION CS: — SPECIFICATION Material: — Durometer: — Temp: — PN: MS28778 MFR: OEM ⚠ VERIFY BEFORE ORDERING Wrong material = failure. Viton for oil/fuel, EPDM for water/steam, Buna-N for general purpose, Silicone for food-grade. Chemical incompatibility causes swelling, brittleness, or rapid degradation ✓ BROKER TIP Durometer (hardness) affects sealing pressure tolerance. Higher Shore A = harder = higher pressure. Standard durometer is 70A — verify if application requires different hardness PARTSTABLE TECHNICAL DRAWING — NOT TO SCALE
TECHNICAL CHARACTERISTICS
PART NAME ASSIGNED BY CONTROLLING AGENCYPACKING, PREFORMED, STRAIGHT THREAD TUBE FITTING BOSS.
OTHER ITEMS IN FSC 5331 — O-ring
Items in the same Federal Supply class. No interchangeability or substitution relationship is implied.
5331-00-001-1971 5331-00-001-1979 5331-00-001-3904 5331-00-001-3905 5331-00-001-3906 5331-00-001-3908 5331-00-001-3923 5331-00-001-3924
SUBSTITUTES & CROSS-REFERENCES 2
MS28778-25Reference document
Same NSN cross-reference
Reference document — Secondary reference
SAE-AS28778Reference document
Same NSN cross-reference
Reference document — Design control — primary reference
LIFECYCLE
NSN statusActive· U.S. Government catalog
Acquisition advice: Terminal item — no further procurement; issued until stock is exhaustedNo demilitarization required
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FREQUENTLY ASKED QUESTIONS
What is MS28778?
MS28778 is a O-RING.
What parts can replace MS28778?
There are 2 known substitutes for MS28778: MS28778-25, SAE-AS28778. Substitute compatibility should be verified for your specific system.
What is the NSN for MS28778?
MS28778 is cataloged in the U.S. Government catalog under NSN 5331-01-490-6342. This indicates validated use in U.S. government and defense supply chains.
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✓ PartsTable — the parts reference. Every fact cited to its source.
PartsTable Design LLC · partstable.com
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.
PartsTable commercial catalog: edition Unified commercial catalog snapshot through 2026-09-28, edition date not on file, retrieved 2026-09-28.