The Nut,plain,hexagon, cataloged under National Stock Number 5310-00-239-7420, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Hydro-Aire Aerospace Corp. Dba Lear Romec Div Lear Romec. Government technical data includes 16 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. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-00-239-7420 |
| Primary Part Number | RB18978 |
| Item Name | Nut,plain,hexagon |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Hydro-Aire Aerospace Corp. Dba Lear Romec Div Lear Romec |
| Status | ACTIVE |
| Width Across Flats | 0.880 INCHES NOMINAL IN |
| Bearing Surface Finish | 125.0 MICROINCHES |
| Thread Series | UN |
| Hole Configuration Style | CONFIGURATION B |
| Material Document and Classification | QQ-A-225/5 FED SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Thread Direction | RIGHT-HAND |
| Nominal Thread Size | 0.562 INCHES IN |
| Nut Height | 0.250 INCHES NOMINAL IN |
| Drilled Hole Diameter | 0.046 INCHES NOMINAL IN |
| Countersink Angle | 90.0 DEGREES NOMINAL NUT |
| Nut Style | HEXAGON |
| Thread Class | 3B |
| Thread Quantity Per Inch | 32 |
| Material | ALUMINUM ALLOY 2017 OVERALL |
| Bearing Surface Type | CHAMFERED |
| Hole Type and Quantity | 3 DRILLED |
| 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 |
|---|---|
| RB18978 PRIMARY | Hydro-Aire Aerospace Corp. Dba Lear Romec Div Lear Romec (USA) |
NSN 5310-00-239-7420 is a Nut,plain,hexagon, manufactured by Hydro-Aire Aerospace Corp. Dba Lear Romec Div Lear Romec, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-00-239-7420 has 1 manufacturer part number on file: RB18978 (Hydro-Aire Aerospace Corp. Dba Lear Romec Div Lear Romec).
Key specifications for RB18978: Width Across Flats: 0.880 INCHES NOMINAL IN; Bearing Surface Finish: 125.0 MICROINCHES; Thread Series: UN; Hole Configuration Style: CONFIGURATION B. 16 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.