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Process steps for metal commemorative COINS
- Oct 05, 2017 -

Metal commemorative coin, as its name suggests, is a coin with value of collection, so what is the process of making metal commemorative coins?

Step 1: selection and identification of materials

Silver generally use 999 pure silver, until the silver 500 silver copper alloy to make, the most widely used in the world is 925 and 900 fineness. Gold coins are usually made from 9999999 or 22K gold or silver alloys.

Step two: fuse strip

The molten metal in the electric furnace is cast into various specifications by continuous casting machine, and then the surface is removed by mechanical milling to remove the impurities, and then cold rolled under the strict requirement of the environment. On the special finishing mill, a bright mirror with a minimal tolerance of thickness is rolled out, and the error is not more than 0.005 millimeters.

Step three: wash the cake and clean it

Put the pieces into the blank cake that the punch presses out, and you must guarantee the smallest burr and the best edge. The surface of the biscuit cake is dried with special detergent, and each cake is weighed. The accuracy of the electronic scale is 0.0001 grams.

Step four: Die

Mold design is a unique link in the process of metal commemorative coin customization. Strictly review the theme, the mint complex pattern, superb work, combined with the use of modern precision equipment, the design intent in mold.

Step five: Imprint

To imprint is clean room with air filtering in a, any tiny dust caused scrap coins, usually on the international imprint scrap rate is 10%, while the large diameter and large area mirror of the coin, the scrap rate is as high as 50%.