The O-Ring, cataloged under National Stock Number 5331-00-641-1821, is classified within Federal Supply Class 5331 (O-ring) of the Hardware and Abrasives group. The manufacturer of record is Control Flow, Inc. Dba Control Flow Inc. Government technical data includes 2 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number for this item, enabling identification through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5331-00-641-1821 |
| Primary Part Number | 6227-78 |
| Item Name | O-Ring |
| FSC / FSG | 5331 / 53 — O-ring |
| Manufacturer | Control Flow, Inc. Dba Control Flow Inc |
| Status | ACTIVE |
| Cross-Sectional Height | 0.250 INCHES NOMINAL IN |
| Material | RUBBER POLYISOPRENE NATURAL CLASS NR OR RUBBER POLYISOPRENE SYNTHETIC CLASS IR |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Part Number | Manufacturer |
|---|---|
| 6227-78 | Control Flow, Inc. Dba Control Flow Inc (USA) |
| Reference | Meaning |
|---|---|
| 6227-78 | 5/9 Secondary reference Control Flow, Inc. Dba Westech Heavy Machinery Division Div Westech Heavy Machinery Division |
| E101286 PC NO 38 | C/1 Advisory reference — outside the item-of-supply concept Control Flow, Inc. Dba Control Flow Inc |
| 6227-78 | 3/9 Design control — primary reference Pullman Standard a Div of Pullman Inc |
NSN 5331-00-641-1821 is a O-Ring, manufactured by Control Flow, Inc. Dba Control Flow Inc, classified under FSC 5331, O-ring. Status: active.
NSN 5331-00-641-1821 has 1 manufacturer part number on file: 6227-78 (Control Flow, Inc. Dba Control Flow Inc).
1 possible match (shared part number, not a government interchangeability claim): 5820-00-966-4541. Verify interchangeability with system specifications before substitution.
Key specifications for 6227-78: Cross-Sectional Height: 0.250 INCHES NOMINAL IN; Material: RUBBER POLYISOPRENE NATURAL CLASS NR OR RUBBER POLYISOPRENE SYNTHETIC CLASS IR. 2 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.
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.