The Inverted Nut,tube Coupling, cataloged under National Stock Number 4730-00-540-6300, 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 16 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 4730-00-540-6300 |
| Primary Part Number | NAS594-20 |
| 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 | 1.375 INCHES NOMINAL IN |
| Material Hardness Rating | 20.0 ROCKWELL C MINIMUM AND 32.0 ROCKWELL C MAXIMUM |
| Seat Angle in Deg | 33.0 |
| Strength Rating | ERR-060 |
| Tube Outside Diameter for Which Designed | 1.250 INCHES NOMINAL IN |
| Style Designator | INVERTED NUT, TUBE, FLARE |
| Material Document and Classification | MIL-S-18732, COND HT-200 MIL SPEC SINGLE MATERIAL RESPONSE |
| Thread Direction | RIGHT-HAND |
| Casehardening Indicator | NOT CASEHARDENED |
| Thread Size | 1.625-12 |
| Screw Thread Series Designator | UN |
| Surface Treatment | PASSIVATE |
| Thread Class | 3A A |
| Material | STEEL COMP 431 |
| Fabrication Method | BAR STOCK, MACHINED |
| Smallest Inside Diameter | 1.270 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 |
|---|---|
| NAS594-20 | Aerofit, Llc (USA) |
| Reference | Meaning |
|---|---|
| NAS594-20 | 3/2 Design control — primary reference U.S. Government activity |
| NAS597 | 3/1 Design control — primary reference U.S. Government activity |
NSN 4730-00-540-6300 is a Inverted Nut,tube Coupling, manufactured by Aerofit, Llc, classified under FSC 4730, Hose, Pipe, Tube, Lubrication, and Railing Fittings. Status: active.
NSN 4730-00-540-6300 has 1 manufacturer part number on file: NAS594-20 (Aerofit, Llc).
Key specifications for NAS594-20: Width Across Flats: 1.375 INCHES NOMINAL IN; Material Hardness Rating: 20.0 ROCKWELL C MINIMUM AND 32.0 ROCKWELL C MAXIMUM; Seat Angle in Deg: 33.0; Strength Rating: ERR-060. 16 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.