The Screw,cap,hexagon Head, cataloged under National Stock Number 5305-01-122-0253, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Progress Rail Locomotive Inc. Dba Progress Rail Switching Services Llc. Government technical data includes 12 specifications, cited from the U.S. Government catalog. The record lists 3 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-01-122-0253 |
| Primary Part Number | 179818 |
| Item Name | Screw,cap,hexagon Head |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Progress Rail Locomotive Inc. Dba Progress Rail Switching Services Llc |
| Status | ACTIVE |
| Head Height | 0.195 INCHES MINIMUM AND 0.211 INCHES MAXIMUM IN |
| Fastener Length | 1.000 INCHES NOMINAL IN |
| Thread Length | 0.845 INCHES MINIMUM AND 0.875 INCHES MAXIMUM IN |
| Material Document and Classification | G-4435-M,CAGE 73183 MFR REF SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.312 INCHES IN |
| Head Style | HEXAGON |
| Thread Direction | RIGHT-HAND |
| Width Between Flats | 0.489 INCHES MINIMUM AND 0.500 INCHES MAXIMUM IN |
| Thread Class | 2A A |
| Thread Quantity Per Inch | 18 |
| Material | STEEL OVERALL |
| Thread Series Designator | UNIFIED NATIONAL COARSE (UNC) |
| 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 |
|---|---|
| 179818 PRIMARY | Progress Rail Locomotive Inc. Dba Progress Rail Switching Services Llc (USA) |
| 179818 PRIMARY | Ferrco Products Inc (USA) |
| 179818 | Engine Systems, Inc. (USA) |
| Reference | Meaning |
|---|---|
| 179818 | 5/9 Secondary reference General Motors Corp Electro-Motive Div |
| 179818 | 5/9 Secondary reference General Motors Corp |
NSN 5305-01-122-0253 is a Screw,cap,hexagon Head, manufactured by Progress Rail Locomotive Inc. Dba Progress Rail Switching Services Llc, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-122-0253 has 3 manufacturer part numbers on file: 179818 (Progress Rail Locomotive Inc. Dba Progress Rail Switching Services Llc), 179818 (Ferrco Products Inc), 179818 (Engine Systems, Inc.).
1 possible match (shared part number, not a government interchangeability claim): 5306-01-207-1283. Verify interchangeability with system specifications before substitution.
Key specifications for 179818: Head Height: 0.195 INCHES MINIMUM AND 0.211 INCHES MAXIMUM IN; Fastener Length: 1.000 INCHES NOMINAL IN; Thread Length: 0.845 INCHES MINIMUM AND 0.875 INCHES MAXIMUM IN; Material Document and Classification: G-4435-M,CAGE 73183 MFR REF SINGLE MATERIAL RESPONSE OVERALL. 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.