The Nut,self-Locking,cap, cataloged under National Stock Number 5310-01-251-1978, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. Government technical data includes 12 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5310-01-251-1978 |
| Item Name | Nut,self-Locking,cap |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Status | ACTIVE |
| Width Across Flats | 0.812 INCHES NOMINAL IN |
| Thread Series | UNIFIED NATIONAL COARSE (UNC) |
| Criticality Code Justification | ZZZY |
| Material Document and Classification | QQ-B-892 FED SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Thread Direction | RIGHT-HAND |
| Nominal Thread Size | 0.500 INCHES IN |
| Specification/standard Data | 81349-MIL-I-45208 GOVERNMENT SPECIFICATION |
| Nut Height | 0.813 INCHES NOMINAL IN |
| Nut Style | CAP |
| Thread Quantity Per Inch | 13 |
| Material | COPPER ALLOY OVERALL |
| Reference Number Differentiating Characteristics | MATERIAL WILL BE IN ACCORDANCE WITH SHIPS PARTS CONTROL CENTER ACTIVITY HX QUALITY CONTROL,MANUFACTURING AND TESTING SPECIFICATIONS |
| 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 |
|---|---|
| N2312 | 3/1 Design control — primary reference Weil Pump Co Inc |
| A1642PC16 | 5/1 Secondary reference Weil Pump Co Inc |
NSN 5310-01-251-1978 is a Nut,self-Locking,cap, classified under FSC 5310, Nuts and Washers. Status: active.
Key specifications for 5310-01-251-1978: Width Across Flats: 0.812 INCHES NOMINAL IN; Thread Series: UNIFIED NATIONAL COARSE (UNC); Criticality Code Justification: ZZZY; Material Document and Classification: QQ-B-892 FED SPEC SINGLE MATERIAL RESPONSE OVERALL. 12 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.