The Screw,machine, cataloged under National Stock Number 5305-01-559-7597, 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 12 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 5305-01-559-7597 |
| Primary Part Number | 91771A156 |
| Item Name | Screw,machine |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Mcmaster-Carr Supply Co |
| Status | ACTIVE |
| Fastener Length | 1.750 INCHES NOMINAL IN |
| Thread Length | 1.750 INCHES NOMINAL IN |
| Nominal Thread Diameter | 0.138 INCHES IN |
| Head Style | FLAT COUNTERSUNK |
| Thread Direction | RIGHT-HAND |
| Screw Material | STEEL COMP 302 OR STEEL COMP 303 OR STEEL COMP 304 OR STEEL COMP 305 OR STEEL COMP 316 |
| 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 | 32 |
| Thread Series Designator | UNIFIED NATIONAL COARSE (UNC) |
| Head Diameter | 0.262 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 |
|---|---|
| 91771A156 PRIMARY | Mcmaster-Carr Supply Co (USA) |
| Reference | Meaning |
|---|---|
| 802027213986-1 | 7/2 Vendor item drawing reference Navy, United States Department of the Dba Naval Surface Warfare Center Div Naval Surface Warfare Center Crane Division |
NSN 5305-01-559-7597 is a Screw,machine, manufactured by Mcmaster-Carr Supply Co, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-559-7597 has 1 manufacturer part number on file: 91771A156 (Mcmaster-Carr Supply Co).
Key specifications for 91771A156: Fastener Length: 1.750 INCHES NOMINAL IN; Thread Length: 1.750 INCHES NOMINAL IN; Nominal Thread Diameter: 0.138 INCHES IN; Head Style: FLAT COUNTERSUNK. 12 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.