Under various sections of the Indian Coinage Act of 1906, the government has 10 different sets of rules "" dated May 11, 1956, October 5, 1989, March 18, 1991, September 9, 1991, October 21, 1991, April 6, 1992, January 9, 1993, April 6, 1993, June 30, 1993 and October 8, 1993. Believe it or not, all of these concern standard weights, shapes, outside diameters, metal composition and number of serrations of coins.
From May 11, 1956 we learn that a rupee must weigh 10 grams, a 50 paise coin must weigh 5 grams, a 25 paise coin must weigh 2.5 grams, a 10 paise coin must weigh 5 grams, a five paise coin must weigh 4 grams, a two paise coin must weigh 3 grams and a one paise coin must weigh 1.5 grams. Deviations of 1/40th of the weight are allowed in either direction.
In 1989, one rupee coins on food and environment were minted. This requires special rules. Hence the rule of October 5, 1989. I am not sure about the weight. But these coins will be made of cupro-nickel alloy, with 75 per cent copper and 25 per cent nickel. They must have 204 serrations. The shape will be circular and the outside diameter will be 26 millimeters.
More specifically, "the outer shape of coin shall be circular and the inner shape of coin shall be heptagonal." Then in 1991, one rupee coins are minted in honour of B.R. Ambedkar. It is not clear to me why the March 18, 1991 could not be consolidated with the October 5, 1989 one. It says exactly the same things about number of serrations, metal composition and shape and outside diameter. The sole difference is that instead of the inner shape being hectagonal, one now has the stipulation, "There shall also be 100 round beads on the periphery of the coin."
In 1991 again, 10 rupee, five rupee and one rupee coins were minted for the Commonwealth Parliamentary Conference. So there is a fresh set of rules from September 9, 1991, completely ignoring what already exists. The metal composition is specified again. 10 rupee coins will have 180 serrations, five rupee coins will have 150 serrations and one rupee coins will have 204 serrrations. (Who decides on the number of serrations and how?) All the coins will be circular. We have already established a diameter of 26 millimeters for one rupee coins. For five rupee coins, the diameter will be 31 millimeters and for 10 rupee coins, the diameter will be 30 millimeters. In addition, instead of 100 round beads on the periphery,
"There shall be 60 beads and one line between two beads on the periphery of the coin." But in 1991, five rupee, two rupee and one rupee coins are again minted for the India Tourism Year. We already have specifications for five rupee and one rupee coins. Hence, on October 21, 1991, these are reproduced yet again. And we are told that for two rupee coins, the shape will be circular with a diameter of 28 millimeters. The number of serrations will be 200.
In 1992, a new set of two rupee coins is minted, for the theme of national integration. Perhaps to differentiate, these cannot be circular with diameters of 28 millimeters. Hence on April 6, 1992, there is a rule to announce that these will be "eleven sided coins (from one corner to the centre of opposite flat side)" and diameters will be 26 millimeters.
Presumably there was a problem with the 31 millimetre diameter on five rupee coins. So the rules issued on January 9, 1993 changed the diameter to 30 millimeters. The number of serrations remained at 150. But there was an additional explanation. "There shall be 48 beads on the periphery of the coin. The edge of the coin shall be milled with serrated or upright milling and security edging. In the centre of the edge there shall be shallow groove with a design inside its two sections separated by blank space. The design shall consist of chain of beads in relief and each bead being followed by two inclined lines in relief. There shall be 24 inclined lines and 24 beads." Such security edging wasn't necessary earlier.
Why can't all such rules be unified?