The Screw,machine, cataloged under National Stock Number 5305-00-917-0993, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Huck International, Inc. Government technical data includes 17 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through both NSN and commercial part number lookups. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5305-00-917-0993 |
| Primary Part Number | 51B221-23 |
| Item Name | Screw,machine |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Huck International, Inc |
| Status | ACTIVE |
| Head Height | 0.103 INCHES MINIMUM AND 0.118 INCHES MAXIMUM IN |
| Fastener Length | 1.423 INCHES MINIMUM AND 1.470 INCHES MAXIMUM IN |
| Screw Material Document and Classification | MIL-S-5000 MIL SPEC 1ST MATERIAL RESPONSE OR MIL-S-5626 MIL SPEC 2ND MATERIAL RESPONSE OR MIL-S-6049 MIL SPEC 3RD MATERIAL RESPONSE |
| Thread Length | 0.276 INCHES MINIMUM IN |
| Hardness Rating | 39.0 ROCKWELL C MINIMUM AND 43.0 ROCKWELL C MAXIMUM |
| Shank Surface Finish | 32.0 MICROINCHES |
| Nominal Thread Diameter | 0.190 INCHES IN |
| Head Style | PAN |
| Thread Direction | RIGHT-HAND |
| Specification/standard Data | 76823-51B221 MANUFACTURERS STANDARD |
| Screw Material | STEEL COMP 4340 OR STEEL COMP 4140 OR STEEL COMP 8740 |
| Minimum Tensile Strength | 180000 POUNDS PER SQUARE INCH LBS |
| Internal Drive Style | TORQUE SET |
| Thread Class | 2A A |
| Thread Quantity Per Inch | 32 |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Head Diameter | 0.381 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 |
|---|---|
| 51B221-23 | Huck International, Inc (USA) |
| 51B221-23 | Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc (CAN) |
| 51B221-23 | Hi-Shear Corporation (USA) |
| 51B221-23 | Howmet Global Fastening Systems Inc (USA) |
| 51B221-23 | Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company (USA) |
| Reference | Meaning |
|---|---|
| 51B221-23 | 5/2 Secondary reference U.S. Government activity |
| 51B221-23 | 3/9 Design control — primary reference Northrop Grumman Systems Corporation Dba Northrop Grumman Is Div Northrop Grumman Aeronautics Systems |
| 51B221-23 | 5/9 Secondary reference U.S. Government activity |
| 51B221-23 | C/1 Advisory reference — outside the item-of-supply concept Northrop Grumman Technical Services, Inc. Dba Defense Systems Sector |
| 51B221-23 | 5/9 Secondary reference U.S. Government activity |
NSN 5305-00-917-0993 is a Screw,machine, manufactured by Huck International, Inc, classified under FSC 5305, Screws. Status: active.
NSN 5305-00-917-0993 has 5 manufacturer part numbers on file: 51B221-23 (Huck International, Inc), 51B221-23 (Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc), 51B221-23 (Hi-Shear Corporation), 51B221-23 (Howmet Global Fastening Systems Inc), 51B221-23 (Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company).
Key specifications for 51B221-23: Head Height: 0.103 INCHES MINIMUM AND 0.118 INCHES MAXIMUM IN; Fastener Length: 1.423 INCHES MINIMUM AND 1.470 INCHES MAXIMUM IN; Screw Material Document and Classification: MIL-S-5000 MIL SPEC 1ST MATERIAL RESPONSE OR MIL-S-5626 MIL SPEC 2ND MATERIAL RESPONSE OR MIL-S-6049 MIL SPEC 3RD MATERIAL RESPONSE; Thread Length: 0.276 INCHES MINIMUM 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.