The Nut,tube Coupling, cataloged under National Stock Number 4730-00-919-4651, is classified within Federal Supply Class 4730 (Hose, Pipe, Tube, Lubrication, and Railing Fittings) of the Pipe, Tubing, Hose, and Fittings group. The manufacturer of record is Sae International Dba Sae International. Government technical data includes 18 specifications, cited from the U.S. Government catalog. The record lists 2 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 20 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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: Cancelled.
| Parameter | Value |
|---|---|
| NSN | 4730-00-919-4651 |
| Primary Part Number | MS21921-4J |
| Item Name | Nut,tube Coupling |
| FSC / FSG | 4730 / 47 — Hose, Pipe, Tube, Lubrication, and Railing Fittings |
| Manufacturer | Sae International Dba Sae International |
| Status | CANCELLED |
| Length to Shoulder | 0.547 INCHES NOMINAL IN |
| Width Across Flats | 0.562 INCHES NOMINAL IN |
| Surface Treatment Document and Classification | MIL-S-5002 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Thread Series | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Material Document and Classification | QQ-S-763,CLASS 304 FED SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Seat Angle | 45.00 DEGREES NOMINAL |
| Thread Direction | RIGHT-HAND |
| Nominal Thread Size | 0.438 INCHES IN |
| Specification/standard Data | 96906-MS21921 GOVERNMENT STANDARD |
| Nut Height | 0.720 INCHES NOMINAL IN |
| Surface Treatment | PASSIVATE OVERALL |
| Nut Style | TUBE COUPLING |
| Thread Class | 3B |
| Thread Quantity Per Inch | 20 |
| Material | STEEL COMP 304 OVERALL |
| Fabrication Method | MACHINED |
| Smallest Inside Diameter | 0.300 INCHES NOMINAL IN |
| Nominal Tube Outside Diameter | 0.250 INCHES IN |
| 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 |
|---|---|
| MS21921-4J PRIMARY | Sae International Dba Sae International (USA) |
| VSF1212-4CC | Fairchild Fasteners Europe - Vsd Gmbh (DEU) |
| Reference | Meaning |
|---|---|
| MS21921-4J | 5/1 Secondary reference Sps Technologies, Llc Dba Airdrome Precision Components |
| MS21921-4J | 5/9 Secondary reference U.S. Government activity |
| 4781013-0004 | C/1 Advisory reference — outside the item-of-supply concept U.S. Government activity |
| 4730009194651 | 5/9 Secondary reference E.c.a Etablissement Centrald'approvisionnement Des Forces Armee |
| 202-21600C4 | 5/9 Secondary reference U.S. Government activity |
| MIL-F-18280 | 5/9 Secondary reference U.S. Government activity |
| MS21921-4J | 5/1 Secondary reference Precision Aircraft Machining Company, Inc. Dba Pamco Div Precision Aircraft Machining Co Dba Pamco |
| CVC4257J4 | 5/9 Secondary reference U.S. Government activity |
| MS21921-4J | 5/1 Secondary reference Wesco Aircraft Hardware Corp. Dba Incora |
| MS21921-4J | 5/9 Secondary reference U.S. Government activity |
| AS21921 | 5/9 Secondary reference Sae International Dba Sae International |
| SAE-AS18280 | 3/1 Design control — primary reference Sae International Dba Sae International |
| 2652291C4 | 5/9 Secondary reference U.S. Government activity |
| AS18280 | 5/9 Secondary reference Sae International Dba Sae International |
| AS21921 | 5/9 Secondary reference U.S. Government activity |
| AS18280 | 5/9 Secondary reference U.S. Government activity |
| 4730PL1454735 | 6/9 Informative reference only Jednolity Indeks Materialowy - Uniform Material Index |
| DV600CJ | 5/9 Secondary reference Deutsch Co the |
| VSF1212-4CC | 5/9 Secondary reference U.S. Government activity |
| MS21921-4J | C/1 Advisory reference — outside the item-of-supply concept U.S. Government activity |
NSN 4730-00-919-4651 is a Nut,tube Coupling, manufactured by Sae International Dba Sae International, classified under FSC 4730, Hose, Pipe, Tube, Lubrication, and Railing Fittings. Status: cancelled.
NSN 4730-00-919-4651 has 2 manufacturer part numbers on file: MS21921-4J (Sae International Dba Sae International), VSF1212-4CC (Fairchild Fasteners Europe - Vsd Gmbh).
1 possible match (shared part number, not a government interchangeability claim): 4730-01-432-1302. Verify interchangeability with system specifications before substitution.
Key specifications for MS21921-4J: Length to Shoulder: 0.547 INCHES NOMINAL IN; Width Across Flats: 0.562 INCHES NOMINAL IN; Surface Treatment Document and Classification: MIL-S-5002 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL; Thread Series: UNIFIED NATIONAL JOINT FINE (UNJF). 18 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 4730-00-919-4651 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.