Representative issue study
Showa 15 (1940) Holed 5 Sen Aluminum
This first aluminum generation succeeds the aluminum-bronze holed type.
昭和十五年五銭アルミニウム貨
- Date
- 昭和十五年 (1940)
- Denomination
- 5 Sen
- Material
- aluminum
- Issue class
- wartime-circulation
Context
Historical and monetary setting
The denomination retained a hole while alloy and later mass changed.
Identification
How to classify the object
Measure mass and hole; inspect oxidation, bends, scratches, and edge loss.
Evidence boundary
What this page does not claim
It is not the heavier aluminum-bronze predecessor.
Issue evidence
Specifications, grading, and authentication
- Mass
- 1.2 g
- Diameter
- 19 mm
- Hole
- 4 mm
- Edge
- plain
- Production year
- 1940
- Legal issue year
- 1940
Material-specific grading
Aluminum: assess oxidation, chalky surfaces, scratches, bends, stains, and edge damage.
Authentication
Verify weight, diameter, thickness, alloy, magnetism, hole, edge, date and character style, die alignment, and evidence of casting, plating, altered dates, fake patina, or modern reproduction. Do not use destructive testing.
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Related Taisho–Showa references
Evidence
Sources and scope
These links support the claims on this page. Source authority does not imply permission to republish source images.
Official specifications, first-issue years, legal-expiry dates, wartime and postwar regular types.
Open sourceImage identity and file-level reuse metadata only; historical claims are verified elsewhere.
Open source