The 1940 half rupee marks the point at which India's silver coinage began its wartime retreat. Nickel had already replaced silver for smaller denominations in 1946 — but the pressures of the Second World War pushed experimental base-metal compositions into production well before that official transition, and silver-plated zinc issues represent that uncomfortable middle ground. Zinc was prone to corrosion and the plating adhesion was inconsistent, which is why surviving examples with intact surfaces are considerably harder to find than mintage figures alone would suggest.
The 1940 half rupee marks the point at which India's silver coinage began its wartime retreat. Nickel had already replaced silver for smaller denominations in 1946 — but the pressures of the Second World War pushed experimental base-metal compositions into production well before that official transition, and silver-plated zinc issues represent that uncomfortable middle ground. Zinc was prone to corrosion and the plating adhesion was inconsistent, which is why surviving examples with intact surfaces are considerably harder to find than mintage figures alone would suggest.