The material of Black colors challenge coin determines the corrosion resistance of the coins. Common materials for the coins are iron, zinc alloy, and copper. The product grades are ordinary, mid-range, and high-end. Among the metal of the product, copper has the most stable chemical properties, so zinc alloy and copper are not easily corroded, which ensures the preservation and commemorative period of coins products from the material.
Coin include coin-type coins and Black colors challenge coins, souvenir coins,metal coins , sport coins,etc.