The shift to nickel brass for this denomination came after years of problems with the earlier ferritic stainless steel version, which proved difficult to strike consistently and caused excessive die wear. India's coin production infrastructure, spread across mints in Mumbai, Kolkata, Hyderabad, and Noida, means that identifying the issuing facility requires reading the small mint mark positioned below the date — each mint used a distinct symbol, and examples from the same year can differ meaningfully in strike quality depending on origin.
The shift to nickel brass for this denomination came after years of problems with the earlier ferritic stainless steel version, which proved difficult to strike consistently and caused excessive die wear. India's coin production infrastructure, spread across mints in Mumbai, Kolkata, Hyderabad, and Noida, means that identifying the issuing facility requires reading the small mint mark positioned below the date — each mint used a distinct symbol, and examples from the same year can differ meaningfully in strike quality depending on origin.