The metallic composition was changed to 90% silver and10% copper, and the weight changed to 2.67 grams (0.094 ounces).

Do all dimes weigh the same?

All U.S. dimes (10-cent pieces) minted since 1965 weigh 2.268 grams (0.080 ounces). ... The metallic composition was changed to 90% silver, 10% copper, and the weight changed to 2.67 grams (0.094 ounces). Between 1853 to 1855, the weight was reduced to 2.49 grams (0.087 ounces) due to rising silver prices.

Do all coins weigh the same?

Some do, but even banks that weigh rolled coins may do so only as a secondary means of verifying the number of coins in a roll. For example, a roll of 50 pennies that are all copper-coated zinc coins made since late 1982 will weigh some 30 grams less than a roll of 50 bronze pennies struck prior to 1983.