The Screw,cap,socket Head, cataloged under National Stock Number 5305-01-641-3974, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Mcmaster-Carr Supply Co. 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 | 5305-01-641-3974 |
| Primary Part Number | 91251A974 |
| Item Name | Screw,cap,socket Head |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Mcmaster-Carr Supply Co |
| Status | ACTIVE |
| Width Across Flats | 0.156 INCHES NOMINAL IN |
| Head Height | 0.190 INCHES NOMINAL IN |
| Fastener Length | 0.437 INCHES NOMINAL IN |
| Thread Length | 0.437 INCHES NOMINAL IN |
| Hardness Rating | 37.0 ROCKWELL C MINIMUM OVERALL |
| Nominal Thread Diameter | 0.190 INCHES IN |
| Head Style | FILLISTER |
| Thread Direction | RIGHT-HAND |
| Color | BLACK OVERALL |
| Surface Treatment | OXIDE OVERALL |
| Minimum Tensile Strength | 170000 POUNDS PER SQUARE INCH LBS |
| Internal Drive Style | HEXAGON |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 24 |
| Material | STEEL OVERALL |
| Thread Series Designator | UNIFIED NATIONAL COARSE (UNC) |
| Head Diameter | 0.312 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 |
|---|---|
| 91251A974 PRIMARY | Mcmaster-Carr Supply Co (USA) |
NSN 5305-01-641-3974 is a Screw,cap,socket Head, manufactured by Mcmaster-Carr Supply Co, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-641-3974 has 1 manufacturer part number on file: 91251A974 (Mcmaster-Carr Supply Co).
Key specifications for 91251A974: Width Across Flats: 0.156 INCHES NOMINAL IN; Head Height: 0.190 INCHES NOMINAL IN; Fastener Length: 0.437 INCHES NOMINAL IN; Thread Length: 0.437 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.