The Screw,close Tolerance, cataloged under National Stock Number 5305-01-048-6098, 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 21 specifications, cited from the U.S. Government catalog. The record lists 5 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-01-048-6098 |
| Primary Part Number | 51B581-7-14H |
| 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 | 1.312 INCHES MINIMUM AND 1.359 INCHES MAXIMUM IN |
| Thread Length | 0.427 INCHES MINIMUM AND 0.494 INCHES MAXIMUM IN |
| Hardness Rating | 39.0 ROCKWELL C MINIMUM AND 43.0 ROCKWELL C MAXIMUM OVERALL |
| Shank Unthreaded Hole Diameter | 0.096 INCHES MINIMUM AND 0.116 INCHES MAXIMUM FIRST HOLE IN |
| Nominal Thread Diameter | 0.438 INCHES IN |
| Head Style | FLAT COUNTERSUNK |
| Thread Direction | RIGHT-HAND |
| Specification/standard Data | 76823-51B58 PROFESSIONAL/INDUSTRIAL ASSOCIATION STANDARD |
| Grip Length | 0.865 INCHES MINIMUM AND 0.885 INCHES MAXIMUM IN |
| Grip Diameter | 0.4360 INCHES MINIMUM AND 0.4370 INCHES MAXIMUM IN |
| Surface Treatment | CADMIUM AND CHROMATE OR CADMIUM OVERALL |
| Minimum Tensile Strength | 180000 POUNDS PER SQUARE INCH LBS |
| Internal Drive Style | OFFSET CRUCIFORM (TORQUE SET) |
| Countersink Angle | 100.0 DEGREES NOMINAL |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 20 |
| Material | STEEL COMP E4340 OR STEEL COMP 4340 OR STEEL COMP 4140 OR STEEL COMP 8740 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Distance From Head Largest Bearing Surface to Shank Hole Center | 1.204 INCHES NOMINAL FIRST HOLE IN |
| Head Diameter | 0.662 INCHES MINIMUM AND 0.668 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 |
|---|---|
| 51B581-7-14H PRIMARY | Northrop Grumman Systems Corporation (USA) |
| 51B581-7-14H | Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company (USA) |
| 51B581-7-14H | Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc (CAN) |
| 51B581-7-14H | Howmet Global Fastening Systems Inc (USA) |
| 51B581-7-14H | Hi-Shear Corporation (USA) |
| Reference | Meaning |
|---|---|
| 51B581-7-14H | 3/9 Design control — primary reference Northrop Grumman Systems Corporation Dba Northrop Grumman Is Div Northrop Grumman Aeronautics Systems |
| 51B581-7-14H | 5/2 Secondary reference U.S. Government activity |
| 51B581-7-14H | 5/9 Secondary reference Northrop Grumman Technical Services, Inc. Dba Defense Systems Sector |
| 51B581-7-14H | 5/9 Secondary reference Sps Technologies Llc Dba PB Fasteners Div PB Fasteners |
| 51B581-7-14H | 5/2 Secondary reference U.S. Government activity |
NSN 5305-01-048-6098 is a Screw,close Tolerance, manufactured by Northrop Grumman Systems Corporation, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-048-6098 has 5 manufacturer part numbers on file: 51B581-7-14H (Northrop Grumman Systems Corporation), 51B581-7-14H (Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company), 51B581-7-14H (Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc), 51B581-7-14H (Howmet Global Fastening Systems Inc), 51B581-7-14H (Hi-Shear Corporation).
Key specifications for 51B581-7-14H: Surface Finish: 32.0 MICROINCHES GRIP; Fastener Length: 1.312 INCHES MINIMUM AND 1.359 INCHES MAXIMUM IN; Thread Length: 0.427 INCHES MINIMUM AND 0.494 INCHES MAXIMUM IN; Hardness Rating: 39.0 ROCKWELL C MINIMUM AND 43.0 ROCKWELL C MAXIMUM OVERALL. 21 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.