The Screw,cap,socket Head, cataloged under National Stock Number 5305-00-078-7021, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Nylok Llc. Government technical data includes 14 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-00-078-7021 |
| Primary Part Number | M34AS420R10C |
| Item Name | Screw,cap,socket Head |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Nylok Llc |
| Status | ACTIVE |
| Fastener Length | 0.625 INCHES NOMINAL IN |
| Thread Length | 0.625 INCHES MAXIMUM IN |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | OVAL COUNTERSUNK |
| Thread Direction | RIGHT-HAND |
| Locking Feature | PATCH THREADS |
| Surface Treatment | CADMIUM AND CHROMATE OR ZINC AND CHROMATE OVERALL |
| Internal Drive Style | CROSS RECESS TYPE 1 |
| Countersink Angle | 80.0 DEGREES MINIMUM AND 82.0 DEGREES MAXIMUM |
| Thread Class | 2A A |
| Thread Quantity Per Inch | 20 |
| Material | STEEL OVERALL |
| Thread Series Designator | UNIFIED NATIONAL COARSE (UNC) |
| Head Diameter | 0.452 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 |
|---|---|
| 8743911 | U S Army Tank Automotive Command Amsta-Im-Mm (USA) |
| M34AS420R10C PRIMARY | Nylok Llc (USA) |
| Reference | Meaning |
|---|---|
| 5305000787021 | 6/9 Informative reference only E.c.a Etablissement Central Des Approvisionnements Des Forces Armees Royales |
| 8743903 | D/9 Drawing number reference only U S Army Tank Automotive Command Amsta-Im-Mm |
NSN 5305-00-078-7021 is a Screw,cap,socket Head, manufactured by Nylok Llc, classified under FSC 5305, Screws. Status: active.
NSN 5305-00-078-7021 has 2 manufacturer part numbers on file: 8743911 (U S Army Tank Automotive Command Amsta-Im-Mm), M34AS420R10C (Nylok Llc).
1 possible match (shared part number, not a government interchangeability claim): 5306-01-022-5953. Verify interchangeability with system specifications before substitution.
Key specifications for M34AS420R10C: Fastener Length: 0.625 INCHES NOMINAL IN; Thread Length: 0.625 INCHES MAXIMUM IN; Nominal Thread Diameter: 0.250 INCHES IN; Head Style: OVAL COUNTERSUNK. 14 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.