The Nut,self-Locking,slotted,hexagon, cataloged under National Stock Number 5310-00-047-2391, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Leonardo Spa Helicopters Division - Production Site. Government technical data includes 15 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through both NSN and commercial part number lookups. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-00-047-2391 |
| Primary Part Number | MS21225-4 |
| Item Name | Nut,self-Locking,slotted,hexagon |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Leonardo Spa Helicopters Division - Production Site |
| Status | ACTIVE |
| Width Across Flats | 0.430 INCHES MINIMUM AND 0.439 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | AMS 2411 ASSN STD SINGLE TREATMENT RESPONSE OVERALL |
| Thread Series | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Temp Rating | 800.0 FAHRENHEIT NOMINAL DEGF |
| Material Document and Classification | AMS 5525 ASSN STD SINGLE MATERIAL RESPONSE OR AMS 5725 ASSN STD SINGLE MATERIAL RESPONSE OR AMS 5737 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Thread Direction | RIGHT-HAND |
| Nominal Thread Size | 0.250 INCHES IN |
| Locking Feature | PREVAILING TORQUE ALL METAL DESIGN |
| Nut Height | 0.266 INCHES MINIMUM AND 0.296 INCHES MAXIMUM IN |
| Surface Treatment | SILVER OVERALL |
| Nut Style | SLOTTED, HEXAGON |
| Thread Class | 3B |
| Thread Quantity Per Inch | 28 |
| Material | IRON ALLOY 660 OVERALL |
| Bearing Surface Type | WASHER FACED |
| 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 |
|---|---|
| MS21225-4 | Leonardo Spa Helicopters Division - Production Site (ITA) |
| Reference | Meaning |
|---|---|
| MS21225-4 | 3/2 Design control — primary reference U.S. Government activity |
| MS21225-4 | 5/9 Secondary reference U.S. Government activity |
| 5310PL2206251 | 6/9 Informative reference only Jednolity Indeks Materialowy - Uniform Material Index |
| Z7764-4 | 5/9 Secondary reference Harvard Industries Inc |
NSN 5310-00-047-2391 is a Nut,self-Locking,slotted,hexagon, manufactured by Leonardo Spa Helicopters Division - Production Site, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-00-047-2391 has 1 manufacturer part number on file: MS21225-4 (Leonardo Spa Helicopters Division - Production Site).
Key specifications for MS21225-4: Width Across Flats: 0.430 INCHES MINIMUM AND 0.439 INCHES MAXIMUM IN; Surface Treatment Document and Classification: AMS 2411 ASSN STD SINGLE TREATMENT RESPONSE OVERALL; Thread Series: UNIFIED NATIONAL JOINT FINE (UNJF); Temp Rating: 800.0 FAHRENHEIT NOMINAL DEGF. 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.