The Screw,cap,socket Head, cataloged under National Stock Number 5305-01-666-3278, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Oshkosh Defense Llc. Government technical data includes 14 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 5305-01-666-3278 |
| Primary Part Number | 4014440006 |
| Item Name | Screw,cap,socket Head |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Oshkosh Defense Llc |
| Status | ACTIVE |
| Width Across Flats | 0.156 INCHES NOMINAL IN |
| Head Height | 0.122 INCHES MINIMUM AND 0.132 INCHES MAXIMUM IN |
| Fastener Length | 1.25 INCHES NOMINAL IN |
| Thread Length | 1.25 INCHES NOMINAL IN |
| Nominal Thread Diameter | 0.25 INCHES IN |
| Head Style | BUTTON |
| Thread Direction | RIGHT-HAND |
| Color | BLACK OVERALL |
| Surface Treatment | PHOSPHATE ZINC OVERALL |
| Internal Drive Style | HEXAGON |
| Thread Quantity Per Inch | 20 |
| Material | STEEL OVERALL |
| Thread Series Designator | UNIFIED NATIONAL COARSE (UNC) |
| Head Diameter | 0.419 INCHES MINIMUM AND 0.437 INCHES MAXIMUM IN |
| 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 |
|---|---|
| 4014440006 PRIMARY | Oshkosh Defense Llc (USA) |
| Reference | Meaning |
|---|---|
| 4014440 | D/9 Drawing number reference only Oshkosh Defense Llc |
NSN 5305-01-666-3278 is a Screw,cap,socket Head, manufactured by Oshkosh Defense Llc, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-666-3278 has 1 manufacturer part number on file: 4014440006 (Oshkosh Defense Llc).
Key specifications for 4014440006: Width Across Flats: 0.156 INCHES NOMINAL IN; Head Height: 0.122 INCHES MINIMUM AND 0.132 INCHES MAXIMUM IN; Fastener Length: 1.25 INCHES NOMINAL IN; Thread Length: 1.25 INCHES NOMINAL IN. 14 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.