The Nut,tube Coupling, cataloged under National Stock Number 4730-01-660-1400, 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 12 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4730-01-660-1400 |
| Primary Part Number | MS21921-20K |
| Item Name | Nut,tube Coupling |
| FSC / FSG | 4730 / 47 — Hose, Pipe, Tube, Lubrication, and Railing Fittings |
| Manufacturer | Sae International Dba Sae International |
| Status | ACTIVE |
| Width Across Flats | 2.0 INCHES NOMINAL IN |
| Thread Series | UNIFIED NATIONAL JOINT (UNJ) |
| Thread Direction | RIGHT-HAND |
| Nominal Thread Size | 1.625 INCHES IN |
| Nut Height | 1.05 INCHES NOMINAL IN |
| Nut Style | TUBE COUPLING |
| Thread Class | 3B |
| Thread Quantity Per Inch | 12 |
| Material | STEEL CORROSION RESISTING NUT |
| Fabrication Method | MACHINED |
| Smallest Inside Diameter | 1.33 INCHES NOMINAL IN |
| Nominal Tube Outside Diameter | 1.25 INCHES IN |
| 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 |
|---|---|
| MS21921-20K PRIMARY | Sae International Dba Sae International (USA) |
| Reference | Meaning |
|---|---|
| SAE-AS21921 | 5/9 Secondary reference Sae International Dba Sae International |
| SAE-AS18280 | 3/1 Design control — primary reference Sae International Dba Sae International |
| MS21921-20K | 5/9 Secondary reference U.S. Government activity |
NSN 4730-01-660-1400 is a Nut,tube Coupling, manufactured by Sae International Dba Sae International, classified under FSC 4730, Hose, Pipe, Tube, Lubrication, and Railing Fittings. Status: active.
NSN 4730-01-660-1400 has 1 manufacturer part number on file: MS21921-20K (Sae International Dba Sae International).
Key specifications for MS21921-20K: Width Across Flats: 2.0 INCHES NOMINAL IN; Thread Series: UNIFIED NATIONAL JOINT (UNJ); Thread Direction: RIGHT-HAND; Nominal Thread Size: 1.625 INCHES IN. 12 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.