The Nut,tube Coupling, cataloged under National Stock Number 4730-01-239-8858, is classified within Federal Supply Class 4730 (Hose, Pipe, Tube, Lubrication, and Railing Fittings) of the Pipe, Tubing, Hose, and Fittings group. Government technical data includes 15 specifications, cited from the U.S. Government catalog. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4730-01-239-8858 |
| Item Name | Nut,tube Coupling |
| FSC / FSG | 4730 / 47 — Hose, Pipe, Tube, Lubrication, and Railing Fittings |
| Status | ACTIVE |
| Length to Shoulder | 0.560 INCHES NOMINAL IN |
| Width Across Flats | 0.625 INCHES NOMINAL IN |
| Thread Series | UNF |
| Seat Angle | 45.0 DEGREES NOMINAL |
| Thread Direction | RIGHT-HAND |
| Nominal Thread Size | 0.250 INCHES IN |
| Specification/standard Data | 96906-MS51823 GOVERNMENT STANDARD |
| Nut Height | 0.719 INCHES NOMINAL IN |
| Nut Style | TUBE COUPLING |
| Thread Class | 2B |
| Thread Quantity Per Inch | 20 |
| Material | STEEL CORROSION RESISTING OVERALL |
| Fabrication Method | FORGED |
| Smallest Inside Diameter | 0.318 INCHES NOMINAL IN |
| Nominal Tube Outside Diameter | 0.313 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 |
| Reference | Meaning |
|---|---|
| MIL-F-18866 | 5/9 Secondary reference U.S. Government activity |
| 5-BU-SS | 5/9 Secondary reference U.S. Government activity |
| MS51823-4SS | 2/2 Government specification standardization U.S. Government activity |
| MIL-DTL-18866 | 4/1 Identification reference U.S. Government activity |
| 5-BU-SS | 5/1 Secondary reference Parker-Hannifin Corporation Dba Pneutronics Div Tube Fittings Division |
NSN 4730-01-239-8858 is a Nut,tube Coupling, classified under FSC 4730, Hose, Pipe, Tube, Lubrication, and Railing Fittings. Status: active.
Key specifications for 4730-01-239-8858: Length to Shoulder: 0.560 INCHES NOMINAL IN; Width Across Flats: 0.625 INCHES NOMINAL IN; Thread Series: UNF; Seat Angle: 45.0 DEGREES NOMINAL. 15 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.