1944–1945 Japan 1 Sen — Shōwa Tin-Zinc Type
Shōwa 19–20 · tin 50% / zinc 50% · official standard 15 mm · 1.3 g
Select a Year
Each calendar year has an independent archive page. The 1945 mintage field is left unnumbered because the supplied Numista table provides no figure and no official annual quantity was located in the consulted official sources.
Wartime Tin-Zinc 1 Sen
Japan Mint Museum records identify this 1 Sen as a tin-zinc alloy of equal parts tin and zinc, produced with 1944 and 1945 dates. Japan Mint history places the type within wartime material substitution and gives the 1944 standard as 15 mm and 1.3 g.
Official Sources & Catalogue Cross-check
Japan Mint — Mint Museum Special Exhibition Exhibit List
Official Japan Mint Museum records identify the 1 Sen tin-zinc type as a 1944–1945 production issue, with composition Sn 500 / Zn 500. The museum list records measured examples at 15.11 mm / 1.33 g for 1944 and 14.98 mm / 1.32 g for 1945.
Japan Mint — 150 Years of History
Japan Mint's official history places the 1 Sen tin-zinc coin in the wartime material-substitution period and gives the Shōwa 19 standard as 15 mm and 1.3 g. The chronology records the 1944 formal establishment of the wartime 1 Sen coin type.
Bank of Japan Currency Museum — Guide to the Exhibits
The Bank of Japan Currency Museum displays the 1944 tin-zinc 1 Sen among wartime money and explains that shortages of nickel and copper led to substitute materials such as aluminum and tin and to simplified wartime coinage.
Numista — Japan 1 Sen, Shōwa (N#9579)
Secondary cross-check for 1944–1945 dating, 15 mm / 1.3 g catalogue standard, 1.51 mm catalogue thickness, plain edge, inscriptions, catalogue identifiers and the supplied annual mintage field. No Numista photograph, valuation table, logo or catalogue prose is reproduced.
Specification rule: Japan Mint official records control composition, type period and the 15 mm / 1.3 g standard. Museum exhibit dimensions and weights are specimen measurements, not a replacement standard. Numista's 1.51 mm thickness is retained only as a secondary catalogue value. Mintage is never inferred where the supplied catalogue field is blank.