The Nut,self-Locking,hexagon, cataloged under National Stock Number 5310-00-138-4261, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. Government technical data includes 18 specifications, cited from the U.S. Government catalog. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 5310-00-138-4261 |
| Item Name | Nut,self-Locking,hexagon |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Status | ACTIVE |
| Lubrication | SOLUBLE LUBRICANT |
| Width Across Flats | 0.430 INCHES MINIMUM AND 0.439 INCHES MAXIMUM IN |
| Bearing Surface Finish | 125.0 MICROINCHES |
| Surface Treatment Document and Classification | QQ-P-416,TY 2,CL 3 FED SPEC SINGLE TREATMENT RESPONSE OVERALL EXCEPT INSERT |
| Thread Series | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Temp Rating | 250.0 FAHRENHEIT NOMINAL DEGF |
| Criticality Code Justification | FEAT |
| Thread Direction | RIGHT-HAND |
| Nominal Thread Size | 0.250 INCHES IN |
| Locking Feature | PREVAILING TORQUE WITH NONMETALLIC INSERT |
| Nut Height | 0.240 INCHES MINIMUM AND 0.360 INCHES MAXIMUM IN |
| Surface Treatment | CADMIUM OVERALL EXCEPT INSERT |
| Countersink Angle | 88.0 DEGREES NOMINAL NUT |
| Nut Style | HEXAGON |
| Thread Class | 3B |
| Thread Quantity Per Inch | 28 |
| Material | COPPER ALLOY 360 OR COPPER ALLOY 260 NUT |
| Bearing Surface Type | CHAMFERED OR WASHER FACED |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | Y |
| Reference | Meaning |
|---|---|
| LS12906-99 | 3/2 Design control — primary reference U.S. Government activity |
| MS21044B4 | 5/9 Secondary reference U.S. Government activity |
| MS21044B4 | 5/1 Secondary reference U.S. Government activity |
NSN 5310-00-138-4261 is a Nut,self-Locking,hexagon, classified under FSC 5310, Nuts and Washers. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 5310-00-982-5065. Verify interchangeability with system specifications before substitution.
Key specifications for 5310-00-138-4261: Lubrication: SOLUBLE LUBRICANT; Width Across Flats: 0.430 INCHES MINIMUM AND 0.439 INCHES MAXIMUM IN; Bearing Surface Finish: 125.0 MICROINCHES; Surface Treatment Document and Classification: QQ-P-416,TY 2,CL 3 FED SPEC SINGLE TREATMENT RESPONSE OVERALL EXCEPT INSERT. 18 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.