The Screw,cap,socket Head, cataloged under National Stock Number 5305-00-151-9490, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Bek, Inc. Dba Level 1 Fasteners. Government technical data includes 19 specifications, cited from the U.S. Government catalog. The record lists 3 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through both NSN and commercial part number lookups. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5305-00-151-9490 |
| Primary Part Number | 509441-66 |
| Item Name | Screw,cap,socket Head |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Bek, Inc. Dba Level 1 Fasteners |
| Status | ACTIVE |
| Surface Finish | 125.0 MICROINCHES OVERALL |
| Width Across Flats | 0.312 INCHES NOMINAL IN |
| Head Height | 0.375 INCHES MAXIMUM IN |
| Fastener Length | 0.750 INCHES NOMINAL IN |
| Thread Length | 0.625 INCHES MINIMUM IN |
| Hardness Rating | 36.0 ROCKWELL C MINIMUM AND 43.0 ROCKWELL C MAXIMUM OVERALL |
| Criticality Code Justification | FEAT |
| 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 | 0.375 INCHES IN |
| Head Style | FLAT CHAMFER |
| Thread Direction | RIGHT-HAND |
| Minimum Yield Strength | 130000 POUNDS PER SQUARE INCH LBS |
| Internal Drive Style | HEXAGON |
| Thread Class | 3A A |
| Test Data Document | 81349-MILI6868 SPECIFICATION (INCLUDES ENGINEERING TYPE BULLETINS, BROCHURES,ETC., THAT REFLECT SPECIFICATION TYPE DATA IN SPECIFICATION FORMAT; EXCLUDES COMMERCIAL CATALOGS, INDUSTRY DIRECTORIES, AND SIMILAR TRADE PUBLICATIONS, REFLECTING GENERAL TYPE DATA ON CERTAIN ENVIRONMENTAL AND PERFORMANCE REQUIREMENTS AND TEST CONDITIONS THAT ARE SHOWN AS "TYPICAL", "AVERAGE", "NOMINAL", ETC.). |
| Thread Quantity Per Inch | 24 |
| Material | STEEL COMP 4140 OR STEEL COMP E4340 OR STEEL COMP 6150 OR STEEL COMP 8735 OR STEEL COMP 8740 OVERALL |
| Thread Series Designator | UNF |
| Head Diameter | 0.563 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 | S |
| Part Number | Manufacturer |
|---|---|
| 509441-66 | Bek, Inc. Dba Level 1 Fasteners (USA) |
| 509441-66 | Apex Manufacturing Company, Inc. Dba Apex Manufacturing Co (USA) |
| 509441-66 | Airtronics, Llc (USA) |
| Reference | Meaning |
|---|---|
| 509441-66 | 3/2 Design control — primary reference U.S. Government activity |
| 509441-66 | 5/9 Secondary reference Apollo Aerospace Components Llc |
| 509441-66 | 5/9 Secondary reference Shur-Kut Supply Corporation Div Shur-Kut Supply Corp. |
| 509441-66 | 5/9 Secondary reference Bmf Corp. Dba Vegas Fastener Manufacturing |
| 509441-66 | 5/9 Secondary reference Metrican Inc Dba Metrix Manufacturing Company |
NSN 5305-00-151-9490 is a Screw,cap,socket Head, manufactured by Bek, Inc. Dba Level 1 Fasteners, classified under FSC 5305, Screws. Status: active.
NSN 5305-00-151-9490 has 3 manufacturer part numbers on file: 509441-66 (Bek, Inc. Dba Level 1 Fasteners), 509441-66 (Apex Manufacturing Company, Inc. Dba Apex Manufacturing Co), 509441-66 (Airtronics, Llc).
Key specifications for 509441-66: Surface Finish: 125.0 MICROINCHES OVERALL; Width Across Flats: 0.312 INCHES NOMINAL IN; Head Height: 0.375 INCHES MAXIMUM IN; Fastener Length: 0.750 INCHES NOMINAL 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.