At one point, I worked out that US dimes, quarters, and half dollars all weigh $20/lb (iirc), which made the task of counting my accumulated change a lot easier.
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Dime: 35 gr
Quarter: 87.5 gr
Half-dollar: 175 gr
Dollar: 350 gr
"Nickel" and "penny" break that pattern, with the first referencing the composition of the coin (originally called a "half-dime"), and penny is a measure of weight, varying by locale. The British penny is 1/240 of a Tower pound (later decimalised to 1/100 in the 1960s), whilst an American pennyweight (used for example in reference to nails) is 1/1000th of a pound.