The Screw,cap,socket Head, cataloged under National Stock Number 5305-01-440-4891, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Carver Pump Company. 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-01-440-4891 |
| Primary Part Number | N-999-6064-B-001 ITEM NO. 44 |
| Item Name | Screw,cap,socket Head |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Carver Pump Company |
| Status | ACTIVE |
| Width Across Flats | 0.188 INCHES NOMINAL IN |
| Head Height | 0.244 INCHES MINIMUM AND 0.250 INCHES MAXIMUM IN |
| Fastener Length | 0.625 INCHES NOMINAL IN |
| Thread Length | 0.525 INCHES MINIMUM AND 0.625 INCHES MAXIMUM IN |
| Hardness Rating | 39.0 ROCKWELL C MINIMUM AND 45.0 ROCKWELL C MAXIMUM OVERALL |
| Material Document and Classification | QQ-N-281 FED SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | FLAT CHAMFER |
| Thread Direction | RIGHT-HAND |
| Minimum Tensile Strength | 180000 POUNDS PER SQUARE INCH LBS |
| Minimum Yield Strength | 155000 POUNDS PER SQUARE INCH LBS |
| Internal Drive Style | HEXAGON |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 20 |
| Material | NICKEL ALLOY K-500 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL COARSE (UNC) |
| Head Diameter | 0.365 INCHES MINIMUM AND 0.375 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 |
|---|---|
| N-999-6064-B-001 ITEM NO. 44 PRIMARY | Carver Pump Company (USA) |
| Reference | Meaning |
|---|---|
| 1/4-20UNC3A QQN -281D CL A OR B | C/1 Advisory reference — outside the item-of-supply concept Zf Industrieantriebe Witten Gmbh |
NSN 5305-01-440-4891 is a Screw,cap,socket Head, manufactured by Carver Pump Company, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-440-4891 has 1 manufacturer part number on file: N-999-6064-B-001 ITEM NO. 44 (Carver Pump Company).
Key specifications for N-999-6064-B-001 ITEM NO. 44: Width Across Flats: 0.188 INCHES NOMINAL IN; Head Height: 0.244 INCHES MINIMUM AND 0.250 INCHES MAXIMUM IN; Fastener Length: 0.625 INCHES NOMINAL IN; Thread Length: 0.525 INCHES MINIMUM AND 0.625 INCHES MAXIMUM 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.