The Setscrew, cataloged under National Stock Number 5305-01-415-1278, 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 18 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-01-415-1278 |
| Primary Part Number | 6408789 FIND 21 |
| Item Name | Setscrew |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Naval Sea Systems Command |
| Status | ACTIVE |
| Width Across Flats | 0.250 INCHES NOMINAL IN |
| Fastener Length | 1.625 INCHES NOMINAL IN |
| Surface Treatment Document and Classification | MIL-F-495 MIL SPEC SINGLE TREATMENT RESPONSE FASTENER |
| Material Document and Classification | MIL-F-18240 MIL SPEC SINGLE MATERIAL RESPONSE LOCKING FEATURE |
| Nominal Thread Diameter | 0.500 INCHES IN |
| Head Style | HEADLESS (SETSCREW) |
| Thread Direction | RIGHT-HAND |
| Point Style | HALF DOG |
| Locking Feature | PATCH THREADS |
| Color | BLACK FASTENER |
| Surface Treatment | OXIDE FASTENER |
| Internal Drive Style | HEXAGON |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 13 |
| Material | PLASTIC POLYAMIDE NYLON LOCKING FEATURE |
| Material | COPPER ALLOY 462 OR COPPER ALLOY 260 OR COPPER ALLOY 270 OR COPPER ALLOY 274 FASTENER |
| Material | COPPER ALLOY 462 OR COPPER ALLOY 260 OR COPPER ALLOY 270 OR COPPER ALLOY 274 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL COARSE (UNC) |
| 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 |
|---|---|
| 6408789 FIND 21 PRIMARY | Naval Sea Systems Command (USA) |
| Reference | Meaning |
|---|---|
| 211059346 | 5/9 Secondary reference Naval Sea Systems Command |
| 211091572 | 5/9 Secondary reference Naval Sea Systems Command |
| 801-6408789-ITEM 21 | 5/9 Secondary reference Naval Sea Systems Command |
NSN 5305-01-415-1278 is a Setscrew, manufactured by Naval Sea Systems Command, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-415-1278 has 1 manufacturer part number on file: 6408789 FIND 21 (Naval Sea Systems Command).
Key specifications for 6408789 FIND 21: Width Across Flats: 0.250 INCHES NOMINAL IN; Fastener Length: 1.625 INCHES NOMINAL IN; Surface Treatment Document and Classification: MIL-F-495 MIL SPEC SINGLE TREATMENT RESPONSE FASTENER; Material Document and Classification: MIL-F-18240 MIL SPEC SINGLE MATERIAL RESPONSE LOCKING FEATURE. 18 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.