The Nut,plain,hexagon, cataloged under National Stock Number 5310-01-385-5644, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Howell Laboratories Inc Dba Howell Laboratories Inc. Government technical data includes 10 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-385-5644 |
| Primary Part Number | 5981 ITEM NO. 6 |
| Item Name | Nut,plain,hexagon |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Howell Laboratories Inc Dba Howell Laboratories Inc |
| Status | ACTIVE |
| Width Across Flats | 0.489 INCHES MINIMUM AND 0.500 INCHES MAXIMUM IN |
| Thread Series | UNIFIED NATIONAL COARSE (UNC) |
| Thread Direction | RIGHT-HAND |
| Nominal Thread Size | 0.312 INCHES IN |
| Nut Height | 0.258 INCHES MINIMUM AND 0.273 INCHES MAXIMUM IN |
| Nut Style | HEXAGON |
| Thread Class | 2B |
| Thread Quantity Per Inch | 18 |
| Material | STEEL CORROSION RESISTING OVERALL |
| 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 | X |
| Part Number | Manufacturer |
|---|---|
| 5981 ITEM NO. 6 PRIMARY | Howell Laboratories Inc Dba Howell Laboratories Inc (USA) |
| Reference | Meaning |
|---|---|
| 5/16-18SSN | 5/9 Secondary reference Howell Laboratories Inc Dba Howell Laboratories Inc |
NSN 5310-01-385-5644 is a Nut,plain,hexagon, manufactured by Howell Laboratories Inc Dba Howell Laboratories Inc, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-385-5644 has 1 manufacturer part number on file: 5981 ITEM NO. 6 (Howell Laboratories Inc Dba Howell Laboratories Inc).
Key specifications for 5981 ITEM NO. 6: Width Across Flats: 0.489 INCHES MINIMUM AND 0.500 INCHES MAXIMUM IN; Thread Series: UNIFIED NATIONAL COARSE (UNC); Thread Direction: RIGHT-HAND; Nominal Thread Size: 0.312 INCHES IN. 10 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.