The Packing Nut, cataloged under National Stock Number 4730-00-491-8916, 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 Northrop Grumman Systems Corporation. 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 4730-00-491-8916 |
| Primary Part Number | A51G10555-11 |
| Item Name | Packing Nut |
| FSC / FSG | 4730 / 47 — Hose, Pipe, Tube, Lubrication, and Railing Fittings |
| Manufacturer | Northrop Grumman Systems Corporation |
| Status | ACTIVE |
| Material Hardness Rating | 29.0 ROCKWELL C MINIMUM AND 42.0 ROCKWELL C MAXIMUM |
| Hole or Slot Quantity | 4 |
| Thread Length | 0.500 INCHES NOMINAL IN |
| Style Designator | ROUND SLOTTED, EXTERNAL THREAD, BOSS |
| Material Document and Classification | AMS 6415 ASSN STD SINGLE MATERIAL RESPONSE |
| Thread Direction | RIGHT-HAND |
| Casehardening Indicator | NOT CASEHARDENED |
| Thread Size | 2 5/8 IN-16 AND 3 IN-16 IN |
| Screw Thread Series Designator | UNIFIED NATIONAL JOINT (UNJ) |
| Surface Treatment | CADMIUM AND CHROMATE |
| Thread Class | 3B AND 3A A |
| Major Unthreaded Outside Diameter | 2.991 INCHES MINIMUM AND 3.300 INCHES MAXIMUM IN |
| Screw Thread Location | INTERNAL AND EXTERNAL |
| Material | STEEL COMP 4340 |
| Slot Width | 0.125 INCHES NOMINAL IN |
| Smallest Inside Diameter | 2.564 INCHES MINIMUM AND 2.573 INCHES MAXIMUM 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 |
|---|---|
| A51G10555-11 PRIMARY | Northrop Grumman Systems Corporation (USA) |
| Reference | Meaning |
|---|---|
| A51G10555-11 | 5/9 Secondary reference Northrop Grumman Systems Corporation |
| A51G10555-11 | 3/9 Design control — primary reference Northrop Grumman Systems Corporation Dba Northrop Grumman Systems Corp Div Northrop Grumman Aeronautics Systems |
NSN 4730-00-491-8916 is a Packing Nut, manufactured by Northrop Grumman Systems Corporation, classified under FSC 4730, Hose, Pipe, Tube, Lubrication, and Railing Fittings. Status: active.
NSN 4730-00-491-8916 has 1 manufacturer part number on file: A51G10555-11 (Northrop Grumman Systems Corporation).
Key specifications for A51G10555-11: Material Hardness Rating: 29.0 ROCKWELL C MINIMUM AND 42.0 ROCKWELL C MAXIMUM; Hole or Slot Quantity: 4; Thread Length: 0.500 INCHES NOMINAL IN; Style Designator: ROUND SLOTTED, EXTERNAL THREAD, BOSS. 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.