dwt
pennyweight
Massexact by definition
The pennyweight is exactly 24 grains, or one twentieth of a troy ounce, which is exactly 1.55517384 grams. Jewellers price scrap and casting work by the pennyweight, and dental alloys are still specified in it.
| 1 dwt | 0.0015551738 kg |
Where the unit came from
It was literally the mass of a silver penny in medieval England: 240 pennies to the troy pound, which is where 240 pence to the pound sterling came from. The abbreviation dwt uses d for denarius, the same d that meant pence in pre-decimal British currency.
Solvers that use mass