The Thumbscrew, cataloged under National Stock Number 5305-01-498-1978, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Fincantieri Marine Systems North America, Inc. Dba Fincantieri Marine Systems North Am. Government technical data includes 12 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. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-01-498-1978 |
| Primary Part Number | MHC526 |
| Item Name | Thumbscrew |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Fincantieri Marine Systems North America, Inc. Dba Fincantieri Marine Systems North Am |
| Status | ACTIVE |
| Head Height | 0.850 INCHES NOMINAL IN |
| Fastener Length | 0.690 INCHES MINIMUM AND 0.810 INCHES MAXIMUM IN |
| Thread Length | 0.750 INCHES NOMINAL IN |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | STAR KNOB |
| Thread Direction | RIGHT-HAND |
| Width Between Flats | 1.375 INCHES NOMINAL IN |
| Thread Class | 2A A |
| Thread Quantity Per Inch | 20 |
| Material | PLASTIC HEAD |
| Material | STEEL FASTENER |
| 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 |
|---|---|
| MHC526 PRIMARY | Fincantieri Marine Systems North America, Inc. Dba Fincantieri Marine Systems North Am (USA) |
| MHC531 PC 7 | Fincantieri Marine Systems North America, Inc. Dba Fincantieri Marine Systems North Am (USA) |
NSN 5305-01-498-1978 is a Thumbscrew, manufactured by Fincantieri Marine Systems North America, Inc. Dba Fincantieri Marine Systems North Am, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-498-1978 has 2 manufacturer part numbers on file: MHC526 (Fincantieri Marine Systems North America, Inc. Dba Fincantieri Marine Systems North Am), MHC531 PC 7 (Fincantieri Marine Systems North America, Inc. Dba Fincantieri Marine Systems North Am).
Key specifications for MHC526: Head Height: 0.850 INCHES NOMINAL IN; Fastener Length: 0.690 INCHES MINIMUM AND 0.810 INCHES MAXIMUM IN; Thread Length: 0.750 INCHES NOMINAL IN; Nominal Thread Diameter: 0.250 INCHES IN. 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.