The Screw,cap,socket Head, cataloged under National Stock Number 5305-01-274-1256, 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 20 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-01-274-1256 |
| Primary Part Number | M63CR420-165 |
| Item Name | Screw,cap,socket Head |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Nylok Llc |
| Status | ACTIVE |
| Width Across Flats | 0.1562 INCHES MINIMUM AND 0.1582 INCHES MAXIMUM IN |
| Head Height | 0.419 INCHES MINIMUM AND 0.437 INCHES MAXIMUM IN |
| Fastener Length | 0.968 INCHES MINIMUM AND 1.000 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | QQ-P-35 FED SPEC SINGLE TREATMENT RESPONSE FASTENER |
| Thread Length | 0.868 INCHES MINIMUM AND 1.000 INCHES MAXIMUM IN |
| Hardness Rating | 80.0 ROCKWELL B MINIMUM FASTENER |
| Material Document and Classification | ASTM A493 ASSN STD ALL MATERIAL RESPONSES FASTENER |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | BUTTON |
| Thread Direction | RIGHT-HAND |
| Locking Feature | PELLET THREADS |
| Surface Treatment | PASSIVATE FASTENER |
| Minimum Tensile Strength | 80000 POUNDS PER SQUARE INCH LBS |
| Internal Drive Style | HEXAGON |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 20 |
| Material | PLASTIC LOCKING FEATURE |
| Material | STEEL COMP 302 OR STEEL COMP 304 OR STEEL COMP 305 FASTENER |
| Thread Series Designator | UNRC |
| Head Diameter | 0.122 INCHES MINIMUM AND 0.132 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 |
|---|---|
| M63CR420-165 PRIMARY | Nylok Llc (USA) |
| 38031K-4C-16 | Sps Technologies, Llc Dba PB Fasteners (USA) |
| Reference | Meaning |
|---|---|
| 13234155 | 7/2 Vendor item drawing reference Us Army Aviation and Missile Command |
| TN33CR040J12PS | 5/9 Secondary reference Torkon Fastener Corp |
NSN 5305-01-274-1256 is a Screw,cap,socket Head, manufactured by Nylok Llc, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-274-1256 has 2 manufacturer part numbers on file: M63CR420-165 (Nylok Llc), 38031K-4C-16 (Sps Technologies, Llc Dba PB Fasteners).
Key specifications for M63CR420-165: Width Across Flats: 0.1562 INCHES MINIMUM AND 0.1582 INCHES MAXIMUM IN; Head Height: 0.419 INCHES MINIMUM AND 0.437 INCHES MAXIMUM IN; Fastener Length: 0.968 INCHES MINIMUM AND 1.000 INCHES MAXIMUM IN; Surface Treatment Document and Classification: QQ-P-35 FED SPEC SINGLE TREATMENT RESPONSE FASTENER. 20 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.