The half dollar coin is a popular coin in the United States. It is the largest coin in the US coinage system and is often used for commemorative coins. The half dollar coin has a diameter of 30.61 millimeters, which is slightly larger than a quarter. It is also slightly thicker than a quarter, measuring 2.15 millimeters in thickness. The half dollar coin is made of a copper-nickel alloy, which is a combination of copper and nickel. This alloy is used to make coins that are more durable and resistant to wear and tear. The half dollar coin is also slightly heavier than a quarter, weighing 11.34 grams. The half dollar coin is a popular coin for collectors and is often used in commemorative coins. It is also a popular coin for vending machines and other coin-operated machines. The half dollar coin is also used in casinos and other gaming establishments. The half dollar coin is a popular coin in the United States and is often used for commemorative coins. It is slightly larger than a quarter and is made of a copper-nickel alloy. The half dollar coin is also slightly heavier than a quarter and is used in vending machines and other coin-operated machines.