The Packing Nut, cataloged under National Stock Number 4730-01-159-7981, 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15 specifications, cited from the U.S. Government catalog. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4730-01-159-7981 |
| Item Name | Packing Nut |
| FSC / FSG | 4730 / 47 — Hose, Pipe, Tube, Lubrication, and Railing Fittings |
| Status | ACTIVE |
| Hole or Slot Quantity | 8 |
| Largest Inside Diameter | 4.900 INCHES NOMINAL IN |
| Thread Length | 1.500 INCHES MAXIMUM IN |
| Style Designator | ROUND, INTERNAL THREAD, SHOULDERED |
| Thread Pitch Diameters | +4.2850 TO 4.3020 INCHES IN |
| Smallest Outside Diameter | 3.000 INCHES MINIMUM AND 3.010 INCHES MAXIMUM IN |
| Thread Direction | RIGHT-HAND |
| Casehardening Indicator | NOT CASEHARDENED |
| Thread Size | 4.375-12 |
| Screw Thread Series Designator | UN |
| Thread Class | 2B |
| Major Unthreaded Outside Diameter | 6.250 INCHES NOMINAL IN |
| Screw Thread Location | INTERNAL |
| Material | NICKEL ALLOY K-500 OR NICKEL ALLOY 502 |
| Slot Width | 0.500 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 |
|---|---|
| 708-4674147 | D/9 Drawing number reference only U.S. Government activity |
| 87553-1504 ITEM 7 | 3/2 Design control — primary reference U.S. Government activity |
| 708-4674147 ITEM 7 | 5/2 Secondary reference U.S. Government activity |
NSN 4730-01-159-7981 is a Packing Nut, classified under FSC 4730, Hose, Pipe, Tube, Lubrication, and Railing Fittings. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 3010-01-194-5261. Verify interchangeability with system specifications before substitution.
Key specifications for 4730-01-159-7981: Hole or Slot Quantity: 8; Largest Inside Diameter: 4.900 INCHES NOMINAL IN; Thread Length: 1.500 INCHES MAXIMUM IN; Style Designator: ROUND, INTERNAL THREAD, SHOULDERED. 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.