The Screw,assembled Washer, cataloged under National Stock Number 5305-00-042-4209, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Rumco Inc. Government technical data includes 21 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 5305-00-042-4209 |
| Primary Part Number | 424209 |
| Item Name | Screw,assembled Washer |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Rumco Inc |
| Status | ACTIVE |
| Head Height | 0.208 INCHES MINIMUM AND 0.230 INCHES MAXIMUM IN |
| Fastener Length | 0.844 INCHES MINIMUM AND 0.875 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | QQ-P-416,TY 1,CL 3 FED SPEC 1ST TREATMENT RESPONSE OR QQ-Z-325,TY 1,CL 3 FED SPEC 2ND TREATMENT RESPONSE OVERALL |
| Primary Washer Outside Diameter | 0.567 INCHES MINIMUM AND 0.590 INCHES MAXIMUM IN |
| Thread Length | 0.733 INCHES MINIMUM AND 0.844 INCHES MAXIMUM IN |
| Hardness Rating | 30.0 ROCKWELL C MINIMUM AND 40.0 ROCKWELL C MAXIMUM FASTENER |
| Hardness Rating | 40.0 ROCKWELL C MINIMUM AND 50.0 ROCKWELL C MAXIMUM PRIMARY WASHER |
| Material Document and Classification | SAE ASSN STD ALL MATERIAL RESPONSES OVERALL |
| Nominal Thread Diameter | 0.312 INCHES IN |
| Head Style | HEXAGON |
| Primary Washer Style | FLAT EXTERNAL TEETH |
| Thread Direction | RIGHT-HAND |
| Primary Washer Material Thickness | 0.028 INCHES MINIMUM AND 0.034 INCHES MAXIMUM IN |
| Width Between Flats | 0.489 INCHES MINIMUM AND 0.500 INCHES MAXIMUM IN |
| Surface Treatment | CADMIUM OR ZINC OVERALL |
| Internal Drive Style | SLOT |
| Thread Class | 2A A |
| Thread Quantity Per Inch | 18 |
| Material | STEEL COMP 1020 OR STEEL COMP 1050 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL COARSE (UNC) |
| Washer Quantity | 1 |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
NSN 5305-00-042-4209 is a Screw,assembled Washer, manufactured by Rumco Inc, classified under FSC 5305, Screws. Status: active.
NSN 5305-00-042-4209 has 2 manufacturer part numbers on file: 424209 (Rumco Inc), 424209 (General Motors Llc Dba General Motors Llc).
Key specifications for 424209: Head Height: 0.208 INCHES MINIMUM AND 0.230 INCHES MAXIMUM IN; Fastener Length: 0.844 INCHES MINIMUM AND 0.875 INCHES MAXIMUM IN; Surface Treatment Document and Classification: QQ-P-416,TY 1,CL 3 FED SPEC 1ST TREATMENT RESPONSE OR QQ-Z-325,TY 1,CL 3 FED SPEC 2ND TREATMENT RESPONSE OVERALL; Primary Washer Outside Diameter: 0.567 INCHES MINIMUM AND 0.590 INCHES MAXIMUM IN. 21 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.