Method of forming blanks for coins

Claim 1

A method for producing blanks suitable for minting into coins or similarly disc-shaped articles, comprising loading a plurality of appropriately disc-shaped steel cores into a perforated container, placing the container in an intermediate metal electroplating bath, said intermediate metal being selected from the group consisting of nickel and zinc, electroplating an intermediate metal coating onto the cores while moving the container angularly about a horizontal axis until the intermediate metal coating has a thickness of at least about 0.005 mm on each opposed face of each core and a thickness on the peripheral edge of each core measured radially in the range of from about 2 to about 4 times the face thickness, placing the container in a copper electroplating bath, electroplating a copper coating onto the cores while moving the container angularly about a horizontal axis until the copper coating has a thickness of at least about 0.05 mm on each opposed face of each core and a thickness on the peripheral edge of each core measured radially in the range of from about 2 to about 4 times the face thickness, removing the plated cores from the container, and heating the plated cores to form a layer of interdiffused copper and intermediate metal and a layer of interdiffused intermediate metal and steel with consequent metallurgical bonding of the copper coating to the intermediate metal coating and of the intermediate metal coating to each steel core and to decrease the hardness of each steel core to less than about 65 on the Rockwell 30T hardness scale.

Claim 2

A method for producing blanks suitable for minting into coins or similarly disc-shaped articles, comprising loading a plurality of appropriately disc-shaped steel cores into a perforated container, placing the container in an intermediate metal electroplating bath, said intermediate metal being selected from the group consisting of nickel and zinc, electroplating an intermediate metal coating onto the cores while moving the container angularly about a horizontal axis until the intermediate metal coating has a thickness of at least about 0.005 mm on each opposed face of each core and a thickness on the peripheral edge of each core measured radially in the range of from about 2 to about 4 times the face thickness, placing the container in a copper electroplating bath, electroplating a copper coating onto the cores while moving the container angularly about a horizontal axis until the copper coating has a thickness of at least about 0.05 mm on each opposed face of each core and a thickness on the peripheral edge of each core measured radially in the range of from about 2 to about 4 times the face thickness, removing the plated cores from the container, and heating the plated cores to form a layer of interdiffused copper and intermediate metal and a layer of interdiffused intermediate metal and steel with consequent metallurgical bonding of the copper coating to the intermediate metal coating and of the intermediate metal coating to each steel core and to decrease the hardness of each steel core to less than about 65 on the Rockwell 30T hardness scale.