The Screw,cap,socket Head, cataloged under National Stock Number 5305-01-209-7173, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is H-K Connecticut Holding Company. Government technical data includes 17 specifications, cited from the U.S. Government catalog. The record lists 2 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5305-01-209-7173 |
| Primary Part Number | 0645-1032-56-UDK |
| Item Name | Screw,cap,socket Head |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | H-K Connecticut Holding Company |
| Status | ACTIVE |
| Width Across Flats | 0.156 INCHES MINIMUM AND 0.159 INCHES MAXIMUM IN |
| Head Height | 0.185 INCHES MINIMUM AND 0.190 INCHES MAXIMUM IN |
| Fastener Length | 3.469 INCHES MINIMUM AND 3.531 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | QQ-P-35 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Thread Length | 3.407 INCHES MAXIMUM IN |
| Hardness Rating | 36.0 ROCKWELL C MINIMUM AND 43.0 ROCKWELL C MAXIMUM OVERALL |
| Nominal Thread Diameter | 0.190 INCHES IN |
| Head Style | FLAT CHAMFER |
| Thread Direction | RIGHT-HAND |
| Surface Treatment | PASSIVATE OVERALL |
| Minimum Tensile Strength | 160000 POUNDS PER SQUARE INCH LBS |
| Internal Drive Style | HEXAGON |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 32 |
| Material | STEEL OVERALL |
| Thread Series Designator | UNRF |
| Head Diameter | 0.303 INCHES MINIMUM AND 0.312 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 |
|---|---|
| 0645-1032-56-UDK PRIMARY | H-K Connecticut Holding Company (USA) |
| 0645-1032-56-UDK PRIMARY | Sps Technologies, Llc Dba PB Fasteners (USA) |
| Reference | Meaning |
|---|---|
| 0645-1032-560UDK | 3/2 Design control — primary reference U.S. Government activity |
| 0645-1032-56-UDK | 5/9 Secondary reference Allen Mfg Co Sub of Chicago Pneumatic Tool Co |
| 0645-1032-56UDK | 3/2 Design control — primary reference U.S. Government activity |
NSN 5305-01-209-7173 is a Screw,cap,socket Head, manufactured by H-K Connecticut Holding Company, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-209-7173 has 2 manufacturer part numbers on file: 0645-1032-56-UDK (H-K Connecticut Holding Company), 0645-1032-56-UDK (Sps Technologies, Llc Dba PB Fasteners).
Key specifications for 0645-1032-56-UDK: Width Across Flats: 0.156 INCHES MINIMUM AND 0.159 INCHES MAXIMUM IN; Head Height: 0.185 INCHES MINIMUM AND 0.190 INCHES MAXIMUM IN; Fastener Length: 3.469 INCHES MINIMUM AND 3.531 INCHES MAXIMUM IN; Surface Treatment Document and Classification: QQ-P-35 FED SPEC SINGLE TREATMENT RESPONSE OVERALL. 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.