The Screw,cap,socket Head, cataloged under National Stock Number 5305-01-646-1641, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. Government technical data includes 14 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-01-646-1641 |
| Item Name | Screw,cap,socket Head |
| FSC / FSG | 5305 / 53 — Screws |
| Status | ACTIVE |
| Width Across Flats | 1.5 MILLIMETERS NOMINAL MM |
| Head Height | 1.9 MILLIMETERS MINIMUM AND 2.0 MILLIMETERS MAXIMUM MM |
| External Thread Tolerance Class | 4G6G |
| Fastener Length | 60.0 MILLIMETERS NOMINAL MM |
| Thread Pitch in Millimeters | 0.4 |
| Thread Length | 16.0 MILLIMETERS MINIMUM AND 18.0 MILLIMETERS MAXIMUM MM |
| Nominal Thread Diameter | 2.0 MILLIMETERS MM |
| Head Style | FLAT CHAMFER |
| Thread Direction | RIGHT-HAND |
| Locking Feature | PELLET OR STRIP OR PATCH THREADS |
| Internal Drive Style | HEXAGON |
| Material | STEEL CORROSION RESISTING OVERALL |
| Thread Series Designator | ISO M |
| Head Diameter | 3.6 MILLIMETERS MINIMUM AND 3.8 MILLIMETERS MAXIMUM MM |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Reference | Meaning |
|---|---|
| B1831DH020060L | 3/2 Design control — primary reference U.S. Government activity |
| ASME B18.3.1M | 3/1 Design control — primary reference U.S. Government activity |
NSN 5305-01-646-1641 is a Screw,cap,socket Head, classified under FSC 5305, Screws. Status: active.
Key specifications for 5305-01-646-1641: Width Across Flats: 1.5 MILLIMETERS NOMINAL MM; Head Height: 1.9 MILLIMETERS MINIMUM AND 2.0 MILLIMETERS MAXIMUM MM; External Thread Tolerance Class: 4G6G; Fastener Length: 60.0 MILLIMETERS NOMINAL MM. 14 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.