The Screw,cap,socket Head, cataloged under National Stock Number 5305-01-355-0203, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Howmet Global Fastening Systems Inc. Div Tridair Products. Government technical data includes 17 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 | 5305-01-355-0203 |
| Primary Part Number | CA21300-4-2 |
| Item Name | Screw,cap,socket Head |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Howmet Global Fastening Systems Inc. Div Tridair Products |
| Status | ACTIVE |
| Surface Finish | 32.0 MICROINCHES BEARING SURFACE OF HEAD |
| Width Across Flats | 0.1565 INCHES MINIMUM AND 0.1587 INCHES MAXIMUM IN |
| Head Height | 0.140 INCHES MINIMUM AND 0.150 INCHES MAXIMUM IN |
| Fastener Length | 0.777 INCHES NOMINAL IN |
| Surface Treatment Document and Classification | QQ-P-35 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Thread Length | 0.487 INCHES MINIMUM AND 0.627 INCHES MAXIMUM IN |
| Material Document and Classification | AMS5732 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | PAN |
| Thread Direction | RIGHT-HAND |
| Surface Treatment | PASSIVATE OVERALL |
| Internal Drive Style | HEXAGON |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 28 |
| Material | IRON ALLOY 660 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL COARSE (UNC) |
| Head Diameter | 0.477 INCHES MINIMUM AND 0.492 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 |
|---|---|
| CA21300-4-2 PRIMARY | Howmet Global Fastening Systems Inc. Div Tridair Products (USA) |
NSN 5305-01-355-0203 is a Screw,cap,socket Head, manufactured by Howmet Global Fastening Systems Inc. Div Tridair Products, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-355-0203 has 1 manufacturer part number on file: CA21300-4-2 (Howmet Global Fastening Systems Inc. Div Tridair Products).
Key specifications for CA21300-4-2: Surface Finish: 32.0 MICROINCHES BEARING SURFACE OF HEAD; Width Across Flats: 0.1565 INCHES MINIMUM AND 0.1587 INCHES MAXIMUM IN; Head Height: 0.140 INCHES MINIMUM AND 0.150 INCHES MAXIMUM IN; Fastener Length: 0.777 INCHES NOMINAL IN. 17 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.