The Inverted Nut,tube Coupling, cataloged under National Stock Number 4730-00-684-7301, 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 Aerofit, Llc. 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4730-00-684-7301 |
| Primary Part Number | NAS591-4 |
| Item Name | Inverted Nut,tube Coupling |
| FSC / FSG | 4730 / 47 — Hose, Pipe, Tube, Lubrication, and Railing Fittings |
| Manufacturer | Aerofit, Llc |
| Status | ACTIVE |
| Width Across Flats | 0.560 INCHES NOMINAL IN |
| Seat Angle in Deg | 33.0 |
| Tube Outside Diameter for Which Designed | 0.250 INCHES NOMINAL IN |
| Style Designator | INVERTED NUT, TUBE, FLARE |
| Thread Direction | RIGHT-HAND |
| Casehardening Indicator | NOT CASEHARDENED |
| Thread Size | 7/16-20 |
| Screw Thread Series Designator | UNF |
| Surface Treatment | ANODIZE |
| Thread Class | 3A A |
| Material | ALUMINUM ALLOY |
| Smallest Inside Diameter | 0.255 INCHES NOMINAL 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 |
|---|---|
| NAS591-4 | Aerofit, Llc (USA) |
| Reference | Meaning |
|---|---|
| 10108435 | 6/9 Informative reference only Nimikkeistokeskus Ncb Finland |
| NAS591-4 | 3/2 Design control — primary reference U.S. Government activity |
NSN 4730-00-684-7301 is a Inverted Nut,tube Coupling, manufactured by Aerofit, Llc, classified under FSC 4730, Hose, Pipe, Tube, Lubrication, and Railing Fittings. Status: active.
NSN 4730-00-684-7301 has 1 manufacturer part number on file: NAS591-4 (Aerofit, Llc).
Key specifications for NAS591-4: Width Across Flats: 0.560 INCHES NOMINAL IN; Seat Angle in Deg: 33.0; Tube Outside Diameter for Which Designed: 0.250 INCHES NOMINAL IN; Style Designator: INVERTED NUT, TUBE, FLARE. 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.