Reeding is the technical term for the little grooves on the edges of a coin. Reeding helps people distinguish coins in their pockets, and helps some machines distinguish coins for their value.

Denomination - Number of Reeds
dime - 118
quarter - 119
half dollar - 150
dollar - 189
Susan B. Anthony dollar - 133
$1 Silver American Eagle bullion - 201
$50 Gold American Eagle one ounce bullion - 161
$25 Gold American Eagle half-ounce bullion - 133
$10 Gold American Eagle quarter-ounce bullion - 109
$5 Gold American Eagle tenth-ounce bullion - 103
$5 Gold commemorative - 106
$10 Gold commemorative (1984 Olympics) - 135