The Nut,union, cataloged under National Stock Number 4730-00-277-3344, 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15 specifications, cited from the U.S. Government catalog. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 5 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4730-00-277-3344 |
| Item Name | Nut,union |
| FSC / FSG | 4730 / 47 — Hose, Pipe, Tube, Lubrication, and Railing Fittings |
| Status | ACTIVE |
| Width Across Flats | 2.250 INCHES NOMINAL IN |
| Shoulder Step Width | 0.281 INCHES NOMINAL IN |
| Shoulder Width | 0.844 INCHES NOMINAL IN |
| Thread Series | UN |
| Maximum Working Pressure Rating and Service for Which Designed | 3000.0 POUNDS PER SQUARE INCH (PSI) OIL AND 3000.0 POUNDS PER SQUARE INCH (PSI) WATER AND 3000.0 POUNDS PER SQUARE INCH (PSI) AIR LBS |
| Thread Direction | RIGHT-HAND |
| Nominal Thread Size | 1.750 INCHES IN |
| Nut Height | 2.000 INCHES NOMINAL IN |
| Nut Style | HEXAGON |
| Thread Class | 2B |
| Thread Quantity Per Inch | 12 |
| Material | NICKEL ALLOY OVERALL |
| Smallest Inside Diameter | 1.188 INCHES NOMINAL IN |
| Reference Number Differentiating Characteristics | AS DIFFERENTIATED BY THD SIZE |
| Shoulder Seat Diameter | 1.625 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 |
| Reference | Meaning |
|---|---|
| 5000S4823-841337PC4 | 3/1 Design control — primary reference Naval Sea Systems Command |
| 511-4684516 ITE | C/1 Advisory reference — outside the item-of-supply concept U.S. Government activity |
| 5000S4823-841337PC4 | 5/9 Secondary reference U.S. Government activity |
NSN 4730-00-277-3344 is a Nut,union, classified under FSC 4730, Hose, Pipe, Tube, Lubrication, and Railing Fittings. Status: active.
5 possible matches (shared part number, not a government interchangeability claim): 4730-00-277-3345, 4730-00-277-3346, 4730-00-277-3347. Verify interchangeability with system specifications before substitution.
Key specifications for 4730-00-277-3344: Width Across Flats: 2.250 INCHES NOMINAL IN; Shoulder Step Width: 0.281 INCHES NOMINAL IN; Shoulder Width: 0.844 INCHES NOMINAL IN; Thread Series: UN. 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.