The Screw,cap,hexagon Head, cataloged under National Stock Number 5305-01-620-7343, 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 12 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 | 5305-01-620-7343 |
| Primary Part Number | B1821BH031F550N |
| Item Name | Screw,cap,hexagon Head |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | The American Society of Mechanical Engineers |
| Status | ACTIVE |
| Head Height | 0.195 INCHES MINIMUM AND 0.211 INCHES MAXIMUM IN |
| Fastener Length | 5.50 INCHES NOMINAL IN |
| Thread Length | 0.875 INCHES NOMINAL IN |
| Nominal Thread Diameter | 0.3125 INCHES IN |
| Head Style | HEXAGON |
| Thread Direction | RIGHT-HAND |
| Specification/standard Data | 05047-ASME B18.2.1-1998 PROFESSIONAL/INDUSTRIAL ASSOCIATION STANDARD |
| Width Between Flats | 0.489 INCHES MINIMUM AND 0.500 INCHES MAXIMUM IN |
| Surface Treatment | ZINC OR CHROMATE OVERALL |
| Thread Class | 2A A |
| Thread Quantity Per Inch | 24 |
| 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 |
|---|---|
| B1821BH031F550N PRIMARY | The American Society of Mechanical Engineers (USA) |
NSN 5305-01-620-7343 is a Screw,cap,hexagon Head, manufactured by The American Society of Mechanical Engineers, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-620-7343 has 1 manufacturer part number on file: B1821BH031F550N (The American Society of Mechanical Engineers).
Key specifications for B1821BH031F550N: Head Height: 0.195 INCHES MINIMUM AND 0.211 INCHES MAXIMUM IN; Fastener Length: 5.50 INCHES NOMINAL IN; Thread Length: 0.875 INCHES NOMINAL IN; Nominal Thread Diameter: 0.3125 INCHES IN. 12 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.