The Screw,close Tolerance, cataloged under National Stock Number 5305-01-047-4000, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Hi-Shear Corporation. Government technical data includes 19 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-01-047-4000 |
| Primary Part Number | 51B334-18 |
| Item Name | Screw,close Tolerance |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Hi-Shear Corporation |
| Status | ACTIVE |
| Surface Finish | 32.0 MICROINCHES GRIP |
| Fastener Length | 1.425 INCHES MINIMUM AND 1.472 INCHES MAXIMUM IN |
| Thread Length | 0.290 INCHES MINIMUM AND 0.357 INCHES MAXIMUM IN |
| Hardness Rating | 39.0 ROCKWELL C MINIMUM AND 43.0 ROCKWELL C MAXIMUM OVERALL |
| Material Document and Classification | -1L-S-5000 MIL SPEC 1ST MATERIAL RESPONSE OR -1L-S-5000 MIL SPEC 2ND MATERIAL RESPONSE OR -1L-S-5626 MIL SPEC 3RD MATERIAL RESPONSE OR -1L-S-6049 MIL SPEC 4TH MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | FLAT COUNTERSUNK |
| Thread Direction | RIGHT-HAND |
| Specification/standard Data | 86823-51B334 PROFESSIONAL/INDUSTRIAL ASSOCIATION STANDARD |
| Grip Length | 1.115 INCHES MINIMUM AND 1.472 INCHES MAXIMUM IN |
| Grip Diameter | 0.2485 INCHES MINIMUM AND 0.2495 INCHES MAXIMUM IN |
| 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 | 28 |
| 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) |
| Head Diameter | 0.451 INCHES MINIMUM AND 0.507 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 |
|---|---|
| 51B334-18 | Hi-Shear Corporation (USA) |
| 51B334-18 | Sps Technologies Llc Dba PB Fasteners Div PB Fasteners (USA) |
| 51B334-18 | Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company (USA) |
| 51B334-18 | Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc (CAN) |
| 51B334-18 | Sps Technologies, Llc Dba PB Fasteners (USA) |
| Reference | Meaning |
|---|---|
| 51B334-18 | 5/2 Secondary reference U.S. Government activity |
| 51B334-18 | C/1 Advisory reference — outside the item-of-supply concept Northrop Grumman Technical Services, Inc. Dba Defense Systems Sector |
| 51B334-18 | 3/9 Design control — primary reference Northrop Grumman Systems Corporation Dba Northrop Grumman Is Div Northrop Grumman Aeronautics Systems |
NSN 5305-01-047-4000 is a Screw,close Tolerance, manufactured by Hi-Shear Corporation, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-047-4000 has 5 manufacturer part numbers on file: 51B334-18 (Hi-Shear Corporation), 51B334-18 (Sps Technologies Llc Dba PB Fasteners Div PB Fasteners), 51B334-18 (Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company), 51B334-18 (Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc), 51B334-18 (Sps Technologies, Llc Dba PB Fasteners).
Key specifications for 51B334-18: Surface Finish: 32.0 MICROINCHES GRIP; Fastener Length: 1.425 INCHES MINIMUM AND 1.472 INCHES MAXIMUM IN; Thread Length: 0.290 INCHES MINIMUM AND 0.357 INCHES MAXIMUM IN; Hardness Rating: 39.0 ROCKWELL C MINIMUM AND 43.0 ROCKWELL C MAXIMUM OVERALL. 19 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.