The Screw,close Tolerance, cataloged under National Stock Number 5305-00-004-5114, 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 18 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5305-00-004-5114 |
| Primary Part Number | 51B581-4-4 |
| Item Name | Screw,close Tolerance |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Northrop Grumman Systems Corporation |
| Status | ACTIVE |
| Surface Finish | 32.0 MICROINCHES GRIP |
| Fastener Length | 0.550 INCHES MINIMUM AND 0.597 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | QQ-P-416,TY 2,CL 3 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Thread Length | 0.290 INCHES MINIMUM AND 0.357 INCHES MAXIMUM IN |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | FLAT COUNTERSUNK |
| Thread Direction | RIGHT-HAND |
| Grip Length | 0.240 INCHES MINIMUM AND 0.260 INCHES MAXIMUM IN |
| Grip Diameter | 0.2485 INCHES MINIMUM AND 0.2495 INCHES MAXIMUM IN |
| Surface Treatment | CADMIUM AND CHROMATE OVERALL |
| Minimum Tensile Strength | 180000 POUNDS PER SQUARE INCH LBS |
| Internal Drive Style | OFFSET CRUCIFORM (TORQUE SET) |
| Countersink Angle | 99.5 DEGREES MINIMUM AND 100.5 DEGREES MAXIMUM |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 28 |
| Material | STEEL COMP E4340 OR STEEL COMP 4340 OR STEEL COMP 6150 OVERALL |
| Thread Series Designator | UNF |
| Head Diameter | 0.394 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 |
|---|---|
| 51B581-4-4 PRIMARY | Northrop Grumman Systems Corporation (USA) |
| Reference | Meaning |
|---|---|
| 51B581-4-4 | 3/9 Design control — primary reference Northrop Grumman Systems Corporation Dba Northrop Grumman Is Div Northrop Grumman Aeronautics Systems |
| 51B581-4-4 | 5/9 Secondary reference Northrop Grumman Technical Services, Inc. Dba Defense Systems Sector |
NSN 5305-00-004-5114 is a Screw,close Tolerance, manufactured by Northrop Grumman Systems Corporation, classified under FSC 5305, Screws. Status: active.
NSN 5305-00-004-5114 has 1 manufacturer part number on file: 51B581-4-4 (Northrop Grumman Systems Corporation).
Key specifications for 51B581-4-4: Surface Finish: 32.0 MICROINCHES GRIP; Fastener Length: 0.550 INCHES MINIMUM AND 0.597 INCHES MAXIMUM IN; Surface Treatment Document and Classification: QQ-P-416,TY 2,CL 3 FED SPEC SINGLE TREATMENT RESPONSE OVERALL; Thread Length: 0.290 INCHES MINIMUM AND 0.357 INCHES MAXIMUM IN. 18 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.