The Nut,self-Locking,plate, cataloged under National Stock Number 5310-01-313-3977, 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 25 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through both NSN and commercial part number lookups. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5310-01-313-3977 |
| Primary Part Number | MS21076L4N |
| Item Name | Nut,self-Locking,plate |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Leonardo Spa Helicopters Division - Production Site |
| Status | ACTIVE |
| Lubrication | DRY FILM LUBRICANT OR SOLUBLE LUBRICANT |
| Plate Thickness | 0.027 INCHES MINIMUM AND 0.090 INCHES MAXIMUM IN |
| Nut Length | 0.801 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | QQ-P-35 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Thread Series | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Plate Width | 0.350 INCHES MINIMUM AND 0.500 INCHES MAXIMUM IN |
| Temp Rating | 450.0 FAHRENHEIT MAXIMUM DEGF |
| Mounting Hole Arrangement Style | 2 HOLES |
| Hardness Rating | 49.0 ROCKWELL C MAXIMUM |
| Criticality Code Justification | AGAV |
| Material Document and Classification | AMS 5525 ASSN STD SINGLE MATERIAL RESPONSE OR AMS 5732 ASSN STD SINGLE MATERIAL RESPONSE OR AMS 5737 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Mounting Hole Diameter | 0.098 INCHES MINIMUM AND 0.103 INCHES MAXIMUM IN |
| Features Provided | FLOATING NUT |
| Thread Direction | RIGHT-HAND |
| Nominal Thread Size | 0.250 INCHES IN |
| Distance From Aperture Center to Mounting Hole Center | 0.276 INCHES MINIMUM AND 0.286 INCHES MAXIMUM IN |
| Locking Feature | PREVAILING TORQUE ALL METAL DESIGN |
| Center to Center Distance Between Mounting Holes Along Length | 0.560 INCHES MINIMUM AND 0.564 INCHES MAXIMUM IN |
| Nut Height | 0.281 INCHES MAXIMUM IN |
| Surface Treatment | PASSIVATE OVERALL |
| Nut Style | PLATE |
| Thread Class | 3B |
| Thread Quantity Per Inch | 28 |
| Material | IRON ALLOY 660 OVERALL |
| Nut Mounting Provision | STRAIGHT HOLES |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | Y |
| Part Number | Manufacturer |
|---|---|
| MS21076L4N | Leonardo Spa Helicopters Division - Production Site (ITA) |
| Reference | Meaning |
|---|---|
| PL405545-01 FN 3 | C/1 Advisory reference — outside the item-of-supply concept Bae Systems Controls Inc. |
| PL405522-01 FN 3 | C/1 Advisory reference — outside the item-of-supply concept Bae Systems Controls Inc. |
| MS21076L4N | 3/2 Design control — primary reference U.S. Government activity |
| MS21076L4N | 5/9 Secondary reference U.S. Government activity |
NSN 5310-01-313-3977 is a Nut,self-Locking,plate, manufactured by Leonardo Spa Helicopters Division - Production Site, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-313-3977 has 1 manufacturer part number on file: MS21076L4N (Leonardo Spa Helicopters Division - Production Site).
Key specifications for MS21076L4N: Lubrication: DRY FILM LUBRICANT OR SOLUBLE LUBRICANT; Plate Thickness: 0.027 INCHES MINIMUM AND 0.090 INCHES MAXIMUM IN; Nut Length: 0.801 INCHES MAXIMUM IN; Surface Treatment Document and Classification: QQ-P-35 FED SPEC SINGLE TREATMENT RESPONSE OVERALL. 25 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.