The Screw,machine, cataloged under National Stock Number 5305-00-809-1665, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Northrop Grumman Systems Corporation. Government technical data includes 14 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5305-00-809-1665 |
| Primary Part Number | 51B221-11 |
| Item Name | Screw,machine |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Northrop Grumman Systems Corporation |
| Status | ACTIVE |
| Head Height | 0.109 INCHES NOMINAL IN |
| Screw Surface Treatment | CADMIUM |
| Fastener Length | 0.963 INCHES NOMINAL IN |
| Thread Length | 0.276 INCHES MINIMUM IN |
| Nominal Thread Diameter | 0.190 INCHES IN |
| Head Style | BUTTON |
| Thread Direction | RIGHT-HAND |
| Screw Material | STEEL |
| Minimum Tensile Strength | 180000 POUNDS PER SQUARE INCH LBS |
| Internal Drive Style | TORQUE SET |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 32 |
| Thread Series Designator | UNF |
| Head Diameter | 0.390 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 |
|---|---|
| 51B221-11 PRIMARY | Northrop Grumman Systems Corporation (USA) |
| Reference | Meaning |
|---|---|
| 51B221-11 | 5/9 Secondary reference Northrop Grumman Technical Services, Inc. Dba Defense Systems Sector |
| 51B221-11 | 3/9 Design control — primary reference Northrop Grumman Systems Corporation Dba Northrop Grumman Is Div Northrop Grumman Aeronautics Systems |
NSN 5305-00-809-1665 is a Screw,machine, manufactured by Northrop Grumman Systems Corporation, classified under FSC 5305, Screws. Status: active.
NSN 5305-00-809-1665 has 1 manufacturer part number on file: 51B221-11 (Northrop Grumman Systems Corporation).
Key specifications for 51B221-11: Head Height: 0.109 INCHES NOMINAL IN; Screw Surface Treatment: CADMIUM; Fastener Length: 0.963 INCHES NOMINAL IN; Thread Length: 0.276 INCHES MINIMUM IN. 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.