The Setscrew, cataloged under National Stock Number 5305-01-421-2039, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Naval Sea Systems Command. Government technical data includes 11 specifications, cited from the U.S. Government catalog. The record lists 2 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-01-421-2039 |
| Primary Part Number | 6405539-FN-42-4 |
| Item Name | Setscrew |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Naval Sea Systems Command |
| Status | ACTIVE |
| Width Across Flats | 0.312 INCHES NOMINAL IN |
| Fastener Length | 0.438 INCHES NOMINAL IN |
| Nominal Thread Diameter | 0.625 INCHES IN |
| Head Style | HEADLESS (SETSCREW) |
| Thread Direction | RIGHT-HAND |
| Point Style | OVAL |
| Internal Drive Style | HEXAGON |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 18 |
| Material | STEEL OVERALL |
| Thread Series Designator | UNF |
| 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 |
|---|---|
| 211059744 | Naval Sea Systems Command (USA) |
| 6405539-FN-42-4 PRIMARY | Naval Sea Systems Command (USA) |
| Reference | Meaning |
|---|---|
| 801-6405539-FN- 42-4 | C/1 Advisory reference — outside the item-of-supply concept Zf Industrieantriebe Witten Gmbh |
| FF-S-200 TYPE 1,STYLE 3 | 5/2 Secondary reference U.S. Government activity |
NSN 5305-01-421-2039 is a Setscrew, manufactured by Naval Sea Systems Command, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-421-2039 has 2 manufacturer part numbers on file: 211059744 (Naval Sea Systems Command), 6405539-FN-42-4 (Naval Sea Systems Command).
Key specifications for 6405539-FN-42-4: Width Across Flats: 0.312 INCHES NOMINAL IN; Fastener Length: 0.438 INCHES NOMINAL IN; Nominal Thread Diameter: 0.625 INCHES IN; Head Style: HEADLESS (SETSCREW). 11 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.