The Screw,cap,socket Head, cataloged under National Stock Number 5305-01-429-9343, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Naval Sea Systems Command. Government technical data includes 15 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number 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through both NSN and commercial part number lookups. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5305-01-429-9343 |
| Primary Part Number | 6406593 FIND MTPD-A21 |
| Item Name | Screw,cap,socket Head |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Naval Sea Systems Command |
| Status | ACTIVE |
| Width Across Flats | 0.375 INCHES NOMINAL IN |
| Head Height | 0.492 INCHES MINIMUM AND 0.500 INCHES MAXIMUM IN |
| Fastener Length | 1.000 INCHES NOMINAL IN |
| Hardness Rating | 28.8 ROCKWELL C MINIMUM AND 38.8 ROCKWELL C MAXIMUM OVERALL |
| Nominal Thread Diameter | 0.500 INCHES IN |
| Head Style | FLAT FILLISTER |
| Locking Feature | PATCH OR PELLET OR STRIP THREADS |
| Minimum Tensile Strength | 135000 POUNDS PER SQUARE INCH LBS |
| Internal Drive Style | HEXAGON |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 13 |
| Material | PLASTIC POLYAMIDE NYLON LOCKING FEATURE |
| Material | STEEL CORROSION RESISTING OVERALL |
| Thread Series Designator | UNIFIED NATIONAL COARSE (UNC) |
| Head Diameter | 0.735 INCHES MINIMUM AND 0.750 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 |
|---|---|
| 6406593 FIND MTPD-A21 PRIMARY | Naval Sea Systems Command (USA) |
| Reference | Meaning |
|---|---|
| 640593-MPTD-A21 | C/1 Advisory reference — outside the item-of-supply concept Naval Sea Systems Command |
| 6406593-MTPD-B21 | C/1 Advisory reference — outside the item-of-supply concept Naval Sea Systems Command |
| 556-6406593-MTPD-A21 | 5/9 Secondary reference Naval Sea Systems Command |
| 218002544 | C/1 Advisory reference — outside the item-of-supply concept Naval Sea Systems Command |
| 6406593-MTPD-A21 | C/1 Advisory reference — outside the item-of-supply concept Naval Sea Systems Command |
NSN 5305-01-429-9343 is a Screw,cap,socket Head, manufactured by Naval Sea Systems Command, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-429-9343 has 1 manufacturer part number on file: 6406593 FIND MTPD-A21 (Naval Sea Systems Command).
Key specifications for 6406593 FIND MTPD-A21: Width Across Flats: 0.375 INCHES NOMINAL IN; Head Height: 0.492 INCHES MINIMUM AND 0.500 INCHES MAXIMUM IN; Fastener Length: 1.000 INCHES NOMINAL IN; Hardness Rating: 28.8 ROCKWELL C MINIMUM AND 38.8 ROCKWELL C MAXIMUM OVERALL. 15 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.