The Screw,cap,socket Head, cataloged under National Stock Number 5305-01-535-4138, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Mcmaster-Carr Supply Co. Government technical data includes 19 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-01-535-4138 |
| Primary Part Number | 91253A309 |
| Item Name | Screw,cap,socket Head |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Mcmaster-Carr Supply Co |
| Status | ACTIVE |
| Width Across Flats | 0.156 INCHES NOMINAL IN |
| Head Height | 0.161 INCHES NOMINAL IN |
| Fastener Length | 1.000 INCHES NOMINAL IN |
| Thread Length | 1.000 INCHES MINIMUM AND 1.500 INCHES MAXIMUM IN |
| Hardness Rating | 39.0 ROCKWELL C MINIMUM AND 44.0 ROCKWELL C MAXIMUM OVERALL |
| Material Document and Classification | ASTM F825 ASSN STD ALL MATERIAL RESPONSES OVERALL |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | FLAT COUNTERSUNK |
| Thread Direction | RIGHT-HAND |
| Color | BLACK OVERALL |
| Surface Treatment | OXIDE OVERALL |
| Minimum Tensile Strength | 144000 POUNDS PER SQUARE INCH LBS |
| Internal Drive Style | HEXAGON |
| Countersink Angle | 82.0 DEGREES NOMINAL |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 28 |
| Material | STEEL OVERALL |
| Thread Series Designator | UNF |
| Head Diameter | 0.531 INCHES NOMINAL 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 |
|---|---|
| 91253A309 | Mcmaster-Carr Supply Co (USA) |
| Reference | Meaning |
|---|---|
| 17-2-0989 | D/9 Drawing number reference only U.S. Government activity |
| 17-2-0989-2 | 3/2 Design control — primary reference U.S. Government activity |
NSN 5305-01-535-4138 is a Screw,cap,socket Head, manufactured by Mcmaster-Carr Supply Co, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-535-4138 has 1 manufacturer part number on file: 91253A309 (Mcmaster-Carr Supply Co).
Key specifications for 91253A309: Width Across Flats: 0.156 INCHES NOMINAL IN; Head Height: 0.161 INCHES NOMINAL IN; Fastener Length: 1.000 INCHES NOMINAL IN; Thread Length: 1.000 INCHES MINIMUM AND 1.500 INCHES MAXIMUM IN. 19 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.