The Screw,cap,socket Head, cataloged under National Stock Number 5305-01-278-1978, 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 24 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-01-278-1978 |
| Primary Part Number | 6300797-04P20N |
| Item Name | Screw,cap,socket Head |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Naval Sea Systems Command |
| Status | ACTIVE |
| Surface Finish | 32.0 MICROINCHES THREADS |
| Surface Finish | 32.0 MICROINCHES GRIP |
| Surface Finish | 63.0 MICROINCHES BEARING SURFACE OF HEAD |
| Head Height | 0.070 INCHES MINIMUM AND 0.080 INCHES MAXIMUM IN |
| Fastener Length | 1.188 INCHES MINIMUM AND 1.250 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | QQ-P-416,TYPE 2,CLASS 2 FED SPEC SINGLE TREATMENT RESPONSE FASTENER |
| Thread Length | 1.138 INCHES MINIMUM AND 1.250 INCHES MAXIMUM IN |
| Hardness Rating | 36.0 ROCKWELL C MINIMUM AND 40.0 ROCKWELL C MAXIMUM FASTENER |
| Material Document and Classification | MIL-S-5626 MIL SPEC 1ST MATERIAL RESPONSE OR MIL-S-8844 MIL SPEC 2ND MATERIAL RESPONSE OR AMS6414 ASSN STD 2ND MATERIAL RESPONSE OR MIL-S-6049 MIL SPEC 3RD MATERIAL RESPONSE FASTENER |
| Material Document and Classification | MIL-F-18240 MIL SPEC SINGLE MATERIAL RESPONSE LOCKING FEATURE |
| Nominal Thread Diameter | 0.112 INCHES IN |
| Head Style | PAN |
| Thread Direction | RIGHT-HAND |
| Specification/standard Data | 80205-NAS1190 PROFESSIONAL/INDUSTRIAL ASSOCIATION STANDARD |
| Locking Feature | PELLET THREADS |
| Surface Treatment | CADMIUM AND CHROMATE FASTENER |
| Minimum Tensile Strength | 160000 POUNDS PER SQUARE INCH LBS |
| Internal Drive Style | CROSS RECESS TYPE 1 |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 40 |
| Material | PLASTIC LOCKING FEATURE |
| Material | STEEL COMP 4140 OR STEEL COMP 4340 OR STEEL COMP 8740 FASTENER |
| Thread Series Designator | UNJC |
| Head Diameter | 0.205 INCHES MINIMUM AND 0.219 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 |
|---|---|
| 6300797-04P20N | Naval Sea Systems Command (USA) |
| Reference | Meaning |
|---|---|
| NAS1190-04P20N | 3/2 Design control — primary reference U.S. Government activity |
NSN 5305-01-278-1978 is a Screw,cap,socket Head, manufactured by Naval Sea Systems Command, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-278-1978 has 1 manufacturer part number on file: 6300797-04P20N (Naval Sea Systems Command).
Key specifications for 6300797-04P20N: Surface Finish: 32.0 MICROINCHES THREADS; Surface Finish: 32.0 MICROINCHES GRIP; Surface Finish: 63.0 MICROINCHES BEARING SURFACE OF HEAD; Head Height: 0.070 INCHES MINIMUM AND 0.080 INCHES MAXIMUM IN. 24 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.