The Setscrew, cataloged under National Stock Number 5305-01-661-3593, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Raytheon Company. 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-01-661-3593 |
| Primary Part Number | 521377-1 |
| Item Name | Setscrew |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Raytheon Company |
| Status | ACTIVE |
| Point Diameter | 0.25 INCHES NOMINAL IN |
| Fastener Length | 0.138 INCHES MINIMUM AND 0.142 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | ASTM A967,TREAT IN AQUEOUS SOLUTION NITRIC 2 ASSN STD SINGLE TREATMENT RESPONSE OVERALL |
| Thread Length | 0.138 INCHES MINIMUM AND 0.142 INCHES MAXIMUM IN |
| Material Document and Classification | ASTM A 582/A 582M ALLOY S30300 COND A ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.25 INCHES IN |
| Head Style | HEADLESS (SETSCREW) |
| Thread Direction | RIGHT-HAND |
| Point Style | FLAT |
| Surface Treatment | PASSIVATE OVERALL |
| Chamfer Angle | 45.0 DEGREES NOMINAL |
| Internal Drive Style | SLOT |
| Thread Class | 2A A |
| Thread Quantity Per Inch | 28 |
| Material | STEEL COMP 303 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 |
|---|---|
| 521377-1 PRIMARY | Raytheon Company (USA) |
| Reference | Meaning |
|---|---|
| 521377 | D/9 Drawing number reference only Raytheon Company |
NSN 5305-01-661-3593 is a Setscrew, manufactured by Raytheon Company, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-661-3593 has 1 manufacturer part number on file: 521377-1 (Raytheon Company).
Key specifications for 521377-1: Point Diameter: 0.25 INCHES NOMINAL IN; Fastener Length: 0.138 INCHES MINIMUM AND 0.142 INCHES MAXIMUM IN; Surface Treatment Document and Classification: ASTM A967,TREAT IN AQUEOUS SOLUTION NITRIC 2 ASSN STD SINGLE TREATMENT RESPONSE OVERALL; Thread Length: 0.138 INCHES MINIMUM AND 0.142 INCHES MAXIMUM IN. 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.