The Screw,shoulder, cataloged under National Stock Number 5305-01-678-5206, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is The American Society of Mechanical Engineers. 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 | 5305-01-678-5206 |
| Primary Part Number | AES20C375B50BB3031 |
| Item Name | Screw,shoulder |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | The American Society of Mechanical Engineers |
| Status | ACTIVE |
| Width Across Flats | 0.1875 INCHES NOMINAL IN |
| Head Height | 0.268 INCHES NOMINAL IN |
| Fastener Length | 2.500 INCHES NOMINAL IN |
| Surface Treatment Document and Classification | ASTM F2833, GRADE 4 ASSN STD SINGLE TREATMENT RESPONSE OVERALL |
| Thread Length | 0.375 INCHES NOMINAL IN |
| Material Document and Classification | ASTM A574 AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM) SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.3125 INCHES IN |
| Head Style | FLAT FILLISTER |
| Thread Direction | RIGHT-HAND |
| Width Between Flats | 0.544 INCHES MINIMUM AND 0.562 INCHES MAXIMUM IN |
| Surface Treatment | ALUMINUM AND ZINC OVERALL |
| Internal Drive Style | HEXAGON |
| Thread Class | 2A A |
| Thread Quantity Per Inch | 18 |
| Material | STEEL CORROSION RESISTING OVERALL |
| Thread Series Designator | UNIFIED NATIONAL COARSE (UNC) |
| Head Diameter | 0.543 INCHES MINIMUM AND 0.562 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 |
|---|---|
| AES20C375B50BB3031 PRIMARY | The American Society of Mechanical Engineers (USA) |
NSN 5305-01-678-5206 is a Screw,shoulder, manufactured by The American Society of Mechanical Engineers, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-678-5206 has 1 manufacturer part number on file: AES20C375B50BB3031 (The American Society of Mechanical Engineers).
Key specifications for AES20C375B50BB3031: Width Across Flats: 0.1875 INCHES NOMINAL IN; Head Height: 0.268 INCHES NOMINAL IN; Fastener Length: 2.500 INCHES NOMINAL IN; Surface Treatment Document and Classification: ASTM F2833, GRADE 4 ASSN STD SINGLE TREATMENT RESPONSE OVERALL. 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.