The O-Ring, cataloged under National Stock Number 5331-00-425-2021, is classified within Federal Supply Class 5331 (O-ring) of the Hardware and Abrasives group. The manufacturer of record is Rolls-Royce Corporation. Government technical data includes 6 specifications, cited from the U.S. Government catalog. The record lists 3 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 7 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Cancelled.
| Parameter | Value |
|---|---|
| NSN | 5331-00-425-2021 |
| Primary Part Number | 6871091-06 |
| Item Name | O-Ring |
| FSC / FSG | 5331 / 53 — O-ring |
| Manufacturer | Rolls-Royce Corporation |
| Status | CANCELLED |
| Temp Rating | -67.0 FAHRENHEIT AND 347.0 FAHRENHEIT DEGF |
| Cross-Sectional Height | 0.075 INCHES MINIMUM AND 0.081 INCHES MAXIMUM IN |
| Outside Diameter | 0.624 INCHES NOMINAL IN |
| Hardness Rating | 75.0 SHORE DUROMETER A NOMINAL |
| Center Hole Diameter | 0.463 INCHES MINIMUM AND 0.473 INCHES MAXIMUM IN |
| Material | RUBBER FLUOROSILICONE CLASS FQ |
| Acquisition Status | CANCELLED |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Part Number | Manufacturer |
|---|---|
| 6871091-06 PRIMARY | Rolls-Royce Corporation (USA) |
| 6871091-06 | Allison Transmission Inc Dba Allison Transmission, Inc (USA) |
| MS9966-06 PRIMARY | Sae International Dba Sae International (USA) |
| Reference | Meaning |
|---|---|
| SAE-AS9966 | 3/1 Design control — primary reference Sae International Dba Sae International |
| MS9966-06 | 5/9 Secondary reference U.S. Government activity |
| MILR3533-906ES | 5/9 Secondary reference Eriks B.v. |
| MS9966-06 | 5/9 Secondary reference U.S. Government activity |
| 5331PL0211458 | 6/9 Informative reference only Jednolity Indeks Materialowy - Uniform Material Index |
NSN 5331-00-425-2021 is a O-Ring, manufactured by Rolls-Royce Corporation, classified under FSC 5331, O-ring. Status: cancelled.
NSN 5331-00-425-2021 has 3 manufacturer part numbers on file: 6871091-06 (Rolls-Royce Corporation), 6871091-06 (Allison Transmission Inc Dba Allison Transmission, Inc), MS9966-06 (Sae International Dba Sae International).
7 possible matches (shared part number, not a government interchangeability claim): 5331-00-582-2571, 5331-01-011-1761, 5331-01-022-8131. Verify interchangeability with system specifications before substitution.
Key specifications for 6871091-06: Temp Rating: -67.0 FAHRENHEIT AND 347.0 FAHRENHEIT DEGF; Cross-Sectional Height: 0.075 INCHES MINIMUM AND 0.081 INCHES MAXIMUM IN; Outside Diameter: 0.624 INCHES NOMINAL IN; Hardness Rating: 75.0 SHORE DUROMETER A NOMINAL. 6 specifications are documented in the U.S. Government catalog.
No hazard code in the DLA record (HMIC N). Hazard information on this page is shown exactly as it appears in the DLA record.
NSN 5331-00-425-2021 is currently cancelled. Check with the Defense Logistics Agency for current availability and authorized substitutes.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-16.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.