The Screw,cap,socket Head, cataloged under National Stock Number 5305-00-857-3530, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Northrop Grumman Systems Corporation. Government technical data includes 15 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. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-00-857-3530 |
| Primary Part Number | S963A4-21 |
| Item Name | Screw,cap,socket Head |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Northrop Grumman Systems Corporation |
| Status | ACTIVE |
| Width Across Flats | 0.157 INCHES NOMINAL IN |
| Fastener Length | 1.768 INCHES NOMINAL IN |
| Thread Length | 0.424 INCHES MINIMUM IN |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | FLAT COUNTERSUNK |
| Thread Direction | RIGHT-HAND |
| Surface Treatment | CADMIUM OVERALL |
| Minimum Tensile Strength | 160000 POUNDS PER SQUARE INCH LBS |
| Internal Drive Style | HEXAGON |
| Countersink Angle | 100.0 DEGREES NOMINAL |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 28 |
| Material | STEEL OVERALL |
| Thread Series Designator | UNF |
| Head Diameter | 0.502 INCHES NOMINAL 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 |
|---|---|
| S963A4-21 PRIMARY | Northrop Grumman Systems Corporation (USA) |
NSN 5305-00-857-3530 is a Screw,cap,socket Head, manufactured by Northrop Grumman Systems Corporation, classified under FSC 5305, Screws. Status: active.
NSN 5305-00-857-3530 has 1 manufacturer part number on file: S963A4-21 (Northrop Grumman Systems Corporation).
Key specifications for S963A4-21: Width Across Flats: 0.157 INCHES NOMINAL IN; Fastener Length: 1.768 INCHES NOMINAL IN; Thread Length: 0.424 INCHES MINIMUM IN; Nominal Thread Diameter: 0.250 INCHES IN. 15 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.