The Screw,machine, cataloged under National Stock Number 5305-00-720-8339, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Aviation Spares and Repairs Ltd. 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5305-00-720-8339 |
| Primary Part Number | NAS623-4-28 |
| Item Name | Screw,machine |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Aviation Spares and Repairs Ltd |
| Status | ACTIVE |
| Head Height | 0.162 INCHES MINIMUM AND 0.175 INCHES MAXIMUM IN |
| Screw Surface Treatment | CADMIUM AND CHROMATE |
| Fastener Length | 2.051 INCHES MINIMUM AND 2.081 INCHES MAXIMUM IN |
| Screw Material Document and Classification | MIL-S-5626 MIL SPEC 1ST MATERIAL RESPONSE OR MIL-S-5000 MIL SPEC 2ND MATERIAL RESPONSE OR MIL-S-6049 MIL SPEC 3RD MATERIAL RESPONSE |
| Thread Length | 0.291 INCHES MINIMUM AND 0.341 INCHES MAXIMUM IN |
| Hardness Rating | 36.0 ROCKWELL C MINIMUM AND 40.0 ROCKWELL C MAXIMUM |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | PAN |
| Thread Direction | RIGHT-HAND |
| Specification/standard Data | 80205-NAS623 PROFESSIONAL/INDUSTRIAL ASSOCIATION STANDARD |
| Screw Material | STEEL COMP 4140 OR STEEL COMP E4340 OR STEEL COMP 8740 |
| Minimum Tensile Strength | 160000 POUNDS PER SQUARE INCH LBS |
| Internal Drive Style | CROSS RECESS TYPE 1 |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 28 |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Head Diameter | 0.473 INCHES MINIMUM AND 0.492 INCHES MAXIMUM IN |
| Screw Surface Treatment Document and Classification | QQ-P-416 TY 2 CL 2 FED SPEC SINGLE TREATMENT RESPONSE |
| 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 |
|---|---|
| NAS623-4-28 | Aviation Spares and Repairs Ltd (GBR) |
| Reference | Meaning |
|---|---|
| 5305PL1020216 | 6/9 Informative reference only Jednolity Indeks Materialowy - Uniform Material Index |
| NAS623-4-28 | 3/2 Design control — primary reference U.S. Government activity |
NSN 5305-00-720-8339 is a Screw,machine, manufactured by Aviation Spares and Repairs Ltd, classified under FSC 5305, Screws. Status: active.
NSN 5305-00-720-8339 has 1 manufacturer part number on file: NAS623-4-28 (Aviation Spares and Repairs Ltd).
Key specifications for NAS623-4-28: Head Height: 0.162 INCHES MINIMUM AND 0.175 INCHES MAXIMUM IN; Screw Surface Treatment: CADMIUM AND CHROMATE; Fastener Length: 2.051 INCHES MINIMUM AND 2.081 INCHES MAXIMUM IN; Screw Material Document and Classification: MIL-S-5626 MIL SPEC 1ST MATERIAL RESPONSE OR MIL-S-5000 MIL SPEC 2ND MATERIAL RESPONSE OR MIL-S-6049 MIL SPEC 3RD MATERIAL RESPONSE. 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.