| Denominations of coins. | Standard or legal weight. | Tolerance allowed by law on individual pieces. | Minimum legal weight of new coins (less tolerance). | ½ per cent, abrasion for 20 years' wear. | Least current weight after 20 years' wear (standard weight less legal limit of abrasion). | Annual abrasion within legal limit. | Actual coefficient of annual abrasion from experiments. |
|---|---|---|---|---|---|---|---|
| GOLD. | |||||||
| Grains. | Grains. | Grains. | Grains. | Grains. | Grains. | Grains. | |
| Double eagle | 516.0 | .50 | 515.50 | 2.58 | 513.42 | .129 | .0860 |
| Eagle | 258.0 | .50 | 257.50 | 1.29 | 256.71 | .0645 | .0430 |
| Half eagle | 129.0 | .25 | 128.75 | .645 | 128.355 | .0322 | .0215 |
| Three-dollar | 77.4 | .25 | 77.15 | .387 | 77.013 | .0193 | .0129 |
| Quarter eagle | 64.5 | .25 | 64.25 | .322 | 64.178 | .0161 | .0107 |
| Dollar | 25.8 | .25 | 25.55 | .129 | *25.671 | .00645 | .0103 |
| SILVER. | |||||||
| Dollar | 412.5 | 1.5 | 411.0 | ||||
| Half dollar | 192.9 | 1.5 | 191.40 | .214 | |||
| Quarter dollar | 96.45 | 1.5 | 94.95 | .137 | |||
| Dime | 38.58 | 1.5 | 37.08 | **.077 | |||
| * The limit of tolerance of the gold dollar being ¼ of a grain (nearly double the limit of abrasion), the gold dollar will continue current until reduced in weight below 25.55 grains. | |||||||
| ** Estimated at ½ of 1 per cent a year. | |||||||