The Screw,cap,socket Head, cataloged under National Stock Number 5305-01-244-6878, 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 20 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-01-244-6878 |
| Primary Part Number | 91251A721 |
| Item Name | Screw,cap,socket Head |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Mcmaster-Carr Supply Co |
| Status | ACTIVE |
| Width Across Flats | 0.375 INCHES MINIMUM AND 0.379 INCHES MAXIMUM IN |
| Head Height | 0.492 INCHES MINIMUM AND 0.500 INCHES MAXIMUM IN |
| Fastener Length | 2.190 INCHES MINIMUM AND 2.250 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | MIL-C-13924,CLASS 1 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Thread Length | 1.500 INCHES MINIMUM IN |
| Hardness Rating | 38.0 ROCKWELL C MINIMUM AND 45.0 ROCKWELL C MAXIMUM OVERALL |
| Nominal Thread Diameter | 0.500 INCHES IN |
| Head Style | FLAT CHAMFER |
| Thread Direction | RIGHT-HAND |
| Specification/standard Data | 80205-NAS1352 PROFESSIONAL/INDUSTRIAL ASSOCIATION STANDARD |
| Color | BLACK OVERALL |
| Surface Treatment | OXIDE OVERALL |
| Minimum Tensile Strength | 170000 POUNDS PER SQUARE INCH LBS |
| Minimum Yield Strength | 150000 POUNDS PER SQUARE INCH LBS |
| Internal Drive Style | HEXAGON |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 13 |
| Material | STEEL OVERALL |
| Thread Series Designator | UNRC |
| Head Diameter | 0.735 INCHES MINIMUM AND 0.750 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 |
|---|---|
| 91251A721 | Mcmaster-Carr Supply Co (USA) |
| Reference | Meaning |
|---|---|
| WG104796 | 3/2 Design control — primary reference U.S. Government activity |
| NAS1352-8-36 | 3/2 Design control — primary reference U.S. Government activity |
NSN 5305-01-244-6878 is a Screw,cap,socket Head, manufactured by Mcmaster-Carr Supply Co, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-244-6878 has 1 manufacturer part number on file: 91251A721 (Mcmaster-Carr Supply Co).
Key specifications for 91251A721: Width Across Flats: 0.375 INCHES MINIMUM AND 0.379 INCHES MAXIMUM IN; Head Height: 0.492 INCHES MINIMUM AND 0.500 INCHES MAXIMUM IN; Fastener Length: 2.190 INCHES MINIMUM AND 2.250 INCHES MAXIMUM IN; Surface Treatment Document and Classification: MIL-C-13924,CLASS 1 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL. 20 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.