The Thumbscrew, cataloged under National Stock Number 5305-01-174-0519, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Howmet Global Fastening Systems Inc. Div Tridair Products. Government technical data includes 21 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-01-174-0519 |
| Primary Part Number | CA21166-4-2 |
| Item Name | Thumbscrew |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Howmet Global Fastening Systems Inc. Div Tridair Products |
| Status | ACTIVE |
| Head Height | 0.625 INCHES NOMINAL IN |
| Fastener Length | 1.059 INCHES NOMINAL IN |
| Shoulder Length | 0.150 INCHES MINIMUM AND 0.290 INCHES MAXIMUM FIRST SHOULDER IN |
| Surface Treatment Document and Classification | QQ-P-35 FED SPEC SINGLE TREATMENT RESPONSE TOP OF HEAD |
| Surface Treatment Document and Classification | QQ-P-416 TY 2 CL 2 MIL SPEC SINGLE TREATMENT RESPONSE FASTENER |
| Shoulder Diameter | 0.247 INCHES MINIMUM AND 0.249 INCHES MAXIMUM FIRST SHOULDER IN |
| Thread Length | 0.487 INCHES NOMINAL IN |
| Shoulder Shape | ROUND FIRST SHOULDER |
| Material Document and Classification | MIL-S-6049 MIL SPEC SINGLE MATERIAL RESPONSE OR MIL-S-5626 MIL SPEC SINGLE MATERIAL RESPONSE FASTENER |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | THUMB NO. 6 |
| Thread Direction | RIGHT-HAND |
| Point Style | POINTLESS |
| Width Between Flats | 0.076 INCHES MINIMUM AND 0.079 INCHES MAXIMUM IN |
| Surface Treatment | CADMIUM AND CHROMATE FASTENER |
| Surface Treatment | PASSIVATE TOP OF HEAD |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 28 |
| Material | STEEL COMP 302B OR STEEL COMP 303 OR STEEL COMP 303 PLUS X OR STEEL COMP 303SE OR STEEL COMP 303CU OR STEEL COMP 303MA OR STEEL COMP 304 OR STEEL COMP 304L TOP OF HEAD |
| Material | STEEL COMP 8740 OR STEEL COMP 4140 FASTENER |
| Thread Series Designator | UNF |
| 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 |
|---|---|
| CA21166-4-2 PRIMARY | Howmet Global Fastening Systems Inc. Div Tridair Products (USA) |
| FIT7833-4-2 | Fastener Innovation Technology, Inc. Dba F I T (USA) |
| Reference | Meaning |
|---|---|
| GS522Y4-2 | 7/2 Vendor item drawing reference Northrop Grumman Systems Corporation |
NSN 5305-01-174-0519 is a Thumbscrew, manufactured by Howmet Global Fastening Systems Inc. Div Tridair Products, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-174-0519 has 2 manufacturer part numbers on file: CA21166-4-2 (Howmet Global Fastening Systems Inc. Div Tridair Products), FIT7833-4-2 (Fastener Innovation Technology, Inc. Dba F I T).
Key specifications for CA21166-4-2: Head Height: 0.625 INCHES NOMINAL IN; Fastener Length: 1.059 INCHES NOMINAL IN; Shoulder Length: 0.150 INCHES MINIMUM AND 0.290 INCHES MAXIMUM FIRST SHOULDER IN; Surface Treatment Document and Classification: QQ-P-35 FED SPEC SINGLE TREATMENT RESPONSE TOP OF HEAD. 21 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.