The Screw,cap,socket Head, cataloged under National Stock Number 5305-00-478-9922, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Leonardo Spa Helicopters Division - Production Site. Government technical data includes 20 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-00-478-9922 |
| Primary Part Number | NAS1189-4T8 |
| Item Name | Screw,cap,socket Head |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Leonardo Spa Helicopters Division - Production Site |
| Status | ACTIVE |
| Surface Finish | 32.0 MICROINCHES THREADS |
| Surface Finish | 32.0 MICROINCHES BEARING SURFACE OF HEAD |
| Fastener Length | 0.469 INCHES MINIMUM AND 0.500 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | QQ-P-416 TY 2 CL 3 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Thread Length | 0.292 INCHES MINIMUM AND 0.394 INCHES MAXIMUM IN |
| Hardness Rating | 36.0 ROCKWELL C MINIMUM AND 40.0 ROCKWELL C MAXIMUM OVERALL |
| Material Document and Classification | MIL-S-5626 MIL SPEC 1ST MATERIAL RESPONSE OR MIL-S-5000 MIL SPEC 2ND MATERIAL RESPONSE OR MIL-S-8503 MIL SPEC 3RD MATERIAL RESPONSE OR MIL-S-6098 MIL SPEC 4TH MATERIAL RESPONSE OR MIL-S-6049 MIL SPEC 5TH MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | FLAT COUNTERSUNK |
| Thread Direction | RIGHT-HAND |
| Specification/standard Data | 80205-NAS1189 PROFESSIONAL/INDUSTRIAL ASSOCIATION STANDARD |
| Surface Treatment | CADMIUM AND CHROMATE OVERALL |
| Minimum Tensile Strength | 160000 POUNDS PER SQUARE INCH LBS |
| Internal Drive Style | OFFSET CRUCIFORM (TORQUE SET) |
| Countersink Angle | 99.0 DEGREES MINIMUM AND 101.0 DEGREES MAXIMUM |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 28 |
| Material | STEEL COMP 4140 OR STEEL COMP E4340 OR STEEL COMP 6150 OR STEEL COMP 8735 OR STEEL COMP 8740 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Head Diameter | 0.442 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 |
|---|---|
| NAS1189-4T8 | Leonardo Spa Helicopters Division - Production Site (ITA) |
| Reference | Meaning |
|---|---|
| LK1189-4T8 | 5/9 Secondary reference Torkon Fastener Corp |
| NAS1189-4T8 | 3/2 Design control — primary reference U.S. Government activity |
| NAS1189-4T8L | 5/9 Secondary reference U.S. Government activity |
NSN 5305-00-478-9922 is a Screw,cap,socket Head, manufactured by Leonardo Spa Helicopters Division - Production Site, classified under FSC 5305, Screws. Status: active.
NSN 5305-00-478-9922 has 1 manufacturer part number on file: NAS1189-4T8 (Leonardo Spa Helicopters Division - Production Site).
Key specifications for NAS1189-4T8: Surface Finish: 32.0 MICROINCHES THREADS; Surface Finish: 32.0 MICROINCHES BEARING SURFACE OF HEAD; Fastener Length: 0.469 INCHES MINIMUM AND 0.500 INCHES MAXIMUM IN; Surface Treatment Document and Classification: QQ-P-416 TY 2 CL 3 FED SPEC SINGLE TREATMENT RESPONSE OVERALL. 20 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.