The Screw,cap,socket Head, cataloged under National Stock Number 5305-00-680-6782, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Ontic Engineering & Manufacturing, Inc Dba Ontic Us. Government technical data includes 19 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-00-680-6782 |
| Primary Part Number | 645009H44S |
| Item Name | Screw,cap,socket Head |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Ontic Engineering & Manufacturing, Inc Dba Ontic Us |
| Status | ACTIVE |
| Width Across Flats | 0.125 INCHES NOMINAL IN |
| Head Height | 0.164 INCHES NOMINAL IN |
| Fastener Length | 0.500 INCHES NOMINAL IN |
| Thread Length | 0.438 INCHES MINIMUM IN |
| Hardness Rating | 38.0 ROCKWELL C MINIMUM AND 42.0 ROCKWELL C MAXIMUM OVERALL |
| Hole Configuration Style | ROUND INTERNAL HEXAGON |
| Nominal Thread Diameter | 0.164 INCHES IN |
| Head Style | FLAT CHAMFER |
| Thread Direction | RIGHT-HAND |
| Surface Treatment | OXIDE OVERALL |
| Internal Drive Style | HEXAGON |
| Thread Class | 2A A |
| Thread Quantity Per Inch | 32 |
| Material | STEEL OVERALL |
| Hole Quantity | 2 |
| Thread Series Designator | UNIFIED NATIONAL COARSE (UNC) |
| Hole Type | DRILLED |
| Hole Diameter | 0.031 INCHES NOMINAL IN |
| Head Diameter | 0.270 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 |
|---|---|
| 645009H44S | Bek, Inc. Dba Level 1 Fasteners (USA) |
| 645009H44S PRIMARY | Ontic Engineering & Manufacturing, Inc Dba Ontic Us (USA) |
| Reference | Meaning |
|---|---|
| 645009H44S | 5/2 Secondary reference U.S. Government activity |
NSN 5305-00-680-6782 is a Screw,cap,socket Head, manufactured by Ontic Engineering & Manufacturing, Inc Dba Ontic Us, classified under FSC 5305, Screws. Status: active.
NSN 5305-00-680-6782 has 2 manufacturer part numbers on file: 645009H44S (Bek, Inc. Dba Level 1 Fasteners), 645009H44S (Ontic Engineering & Manufacturing, Inc Dba Ontic Us).
Key specifications for 645009H44S: Width Across Flats: 0.125 INCHES NOMINAL IN; Head Height: 0.164 INCHES NOMINAL IN; Fastener Length: 0.500 INCHES NOMINAL IN; Thread Length: 0.438 INCHES MINIMUM IN. 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.