The Nut,tube Coupling, cataloged under National Stock Number 4730-01-641-1540, 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 Naval Inventory Control Point Mechanicsburg. Government technical data includes 14 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4730-01-641-1540 |
| Primary Part Number | MS51823-3SSL1 |
| Item Name | Nut,tube Coupling |
| FSC / FSG | 4730 / 47 — Hose, Pipe, Tube, Lubrication, and Railing Fittings |
| Manufacturer | Naval Inventory Control Point Mechanicsburg |
| Status | ACTIVE |
| Length to Shoulder | 0.537 INCHES NOMINAL IN |
| Width Across Flats | 0.563 INCHES NOMINAL IN |
| Thread Series | UNF |
| Criticality Code Justification | ZZZY |
| Thread Direction | RIGHT-HAND |
| Nominal Thread Size | 0.438 INCHES IN |
| Nut Height | 0.700 INCHES NOMINAL IN |
| Nut Style | TUBE COUPLING |
| Thread Class | 2B |
| Thread Quantity Per Inch | 20 |
| Material | STEEL CORROSION RESISTING OVERALL |
| Smallest Inside Diameter | 0.255 INCHES NOMINAL IN |
| Nominal Tube Outside Diameter | 0.250 INCHES IN |
| Reference Number Differentiating Characteristics | MATERIAL CONTROLLED IAW NAVSEA 0948-LP-045-7010 MATERIAL CONTROL STANDARD FOR LEVEL I ITEMS |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | S |
| Part Number | Manufacturer |
|---|---|
| MS51823-3SSL1 | Naval Inventory Control Point Mechanicsburg (USA) |
| Reference | Meaning |
|---|---|
| MS51823-3SS | 3/1 Design control — primary reference U.S. Government activity |
NSN 4730-01-641-1540 is a Nut,tube Coupling, manufactured by Naval Inventory Control Point Mechanicsburg, classified under FSC 4730, Hose, Pipe, Tube, Lubrication, and Railing Fittings. Status: active.
NSN 4730-01-641-1540 has 1 manufacturer part number on file: MS51823-3SSL1 (Naval Inventory Control Point Mechanicsburg).
Key specifications for MS51823-3SSL1: Length to Shoulder: 0.537 INCHES NOMINAL IN; Width Across Flats: 0.563 INCHES NOMINAL IN; Thread Series: UNF; Criticality Code Justification: ZZZY. 14 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.