The Packing Nut, cataloged under National Stock Number 4730-00-977-8591, 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 14 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government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 | 4730-00-977-8591 |
| Item Name | Packing Nut |
| FSC / FSG | 4730 / 47 — Hose, Pipe, Tube, Lubrication, and Railing Fittings |
| Status | ACTIVE |
| Length to Shoulder | 0.094 INCHES NOMINAL IN |
| Width Across Flats | 0.750 INCHES NOMINAL IN |
| Largest Inside Diameter | 0.453 INCHES NOMINAL IN |
| Thread Length | 0.266 INCHES NOMINAL IN |
| Style Designator | HEXAGON, EXTERNAL THREAD, INTERNAL SHOUL DER |
| Thread Direction | RIGHT-HAND |
| Casehardening Indicator | NOT CASEHARDENED |
| Thread Size | 0.625-27 |
| Screw Thread Series Designator | UNS |
| Thread Class | 2A A |
| Major Unthreaded Outside Diameter | 0.594 INCHES NOMINAL IN |
| Screw Thread Location | EXTERNAL |
| Material | STEEL CORROSION RESISTING |
| Smallest Inside Diameter | 0.266 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 |
|---|---|
| 0502-16 | 3/2 Design control — primary reference U.S. Government activity |
NSN 4730-00-977-8591 is a Packing Nut, classified under FSC 4730, Hose, Pipe, Tube, Lubrication, and Railing Fittings. Status: active.
2 possible matches (shared part number, not a government interchangeability claim): 6515-01-139-9159, 3110-01-319-9187. Verify interchangeability with system specifications before substitution.
Key specifications for 4730-00-977-8591: Length to Shoulder: 0.094 INCHES NOMINAL IN; Width Across Flats: 0.750 INCHES NOMINAL IN; Largest Inside Diameter: 0.453 INCHES NOMINAL IN; Thread Length: 0.266 INCHES NOMINAL IN. 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.