The Nut,plain,square, cataloged under National Stock Number 5310-00-208-1971, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. Government technical data includes 13 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5310-00-208-1971 |
| Item Name | Nut,plain,square |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Status | ACTIVE |
| Width Across Flats | 0.425 INCHES MINIMUM AND 0.4375 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | QQ-P-416,TY 2,CL 3 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Thread Series | UNIFIED NATIONAL COARSE (UNC) |
| Thread Direction | RIGHT-HAND |
| Nominal Thread Size | 0.250 INCHES IN |
| Nondefinitive Spec/std Data | B-2 TYPE |
| Nut Height | 0.203 INCHES MINIMUM AND 0.235 INCHES MAXIMUM IN |
| Surface Treatment | CADMIUM OVERALL |
| Nut Style | SQUARE |
| Thread Class | 2B |
| Thread Quantity Per Inch | 20 |
| Material | STEEL 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 |
| Reference | Meaning |
|---|---|
| ESE337CITEM8 | 3/2 Design control — primary reference U.S. Government activity |
| FFB571 | 4/1 Identification reference U.S. Government activity |
NSN 5310-00-208-1971 is a Nut,plain,square, classified under FSC 5310, Nuts and Washers. Status: active.
Key specifications for 5310-00-208-1971: Width Across Flats: 0.425 INCHES MINIMUM AND 0.4375 INCHES MAXIMUM IN; Surface Treatment Document and Classification: QQ-P-416,TY 2,CL 3 FED SPEC SINGLE TREATMENT RESPONSE OVERALL; Thread Series: UNIFIED NATIONAL COARSE (UNC); Thread Direction: RIGHT-HAND. 13 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.