The Nut,union, cataloged under National Stock Number 4730-01-031-8872, 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15 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4730-01-031-8872 |
| Item Name | Nut,union |
| FSC / FSG | 4730 / 47 — Hose, Pipe, Tube, Lubrication, and Railing Fittings |
| Status | ACTIVE |
| Width Across Flats | 4.375 INCHES NOMINAL IN |
| Shoulder Step Width | 0.375 INCHES NOMINAL IN |
| Shoulder Width | 0.313 INCHES NOMINAL IN |
| Thread Series | UN |
| Criticality Code Justification | ZZZY |
| Thread Direction | RIGHT-HAND |
| Nominal Thread Size | 3.750 INCHES IN |
| Nut Height | 1.500 INCHES NOMINAL IN |
| Nut Style | HEXAGON |
| Thread Class | 3B |
| Thread Quantity Per Inch | 12 |
| Material | NICKEL ALLOY OR STEEL CORROSION RESISTING OVERALL |
| Smallest Inside Diameter | 3.190 INCHES NOMINAL IN |
| Reference Number Differentiating Characteristics | QUALITY CONTROL IN ACCORDANCE WITH NAVSHIPS 0948-045-7010 MATERIAL IDENTIFICATION AND CONTROL INSTRUCTION FOR LEVEL 1 ITEMS |
| Shoulder Seat Diameter | 3.750 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 | S |
| Reference | Meaning |
|---|---|
| 810-1385884 PIECE 8 2INL1 | 5/1 Secondary reference Naval Inventory Control Point Mechanicsburg |
| 810-1385884 PIECE 8 2IN | 3/1 Design control — primary reference Naval Sea Systems Command |
NSN 4730-01-031-8872 is a Nut,union, classified under FSC 4730, Hose, Pipe, Tube, Lubrication, and Railing Fittings. Status: active.
Key specifications for 4730-01-031-8872: Width Across Flats: 4.375 INCHES NOMINAL IN; Shoulder Step Width: 0.375 INCHES NOMINAL IN; Shoulder Width: 0.313 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.