About Minting Medals

posted Aug 27, 2013, 10:52 AM by Abdallah Absi

About Minting Medals





What is Minting?

Minting is the process of producing medals by pressing a blank metal disk using a pressing machine against a stamping steel die which is a tool that has an engraved impression on its surface. Through this process the die strikes an image or a relief on the blank, turning it into a coin or a medal.

View a video about minting medals here.


Making the Blanks

Strips of metal (brass, copper, nickel silver, silver or gold) of specified width are cut from metal sheets of specified thickness using a shear cutter. The strips are then cut using cutting dies to produce blanks. If a Proof or Brilliant finish is desired then the blank planchets are polished (by a rotating brush).



Brass strips are cut from brass sheets of specified thickness

Brass blanks are cut from brass sheets with a specified thickness, different cutting dies are produced to cut different sizes and shapes



Brass blanks are cut from brass sheets with the required thickness, different cutting dies are produced to cut different sizes and shapes

 

A rotating brush is used to polish the blanks incase a proof-like or brilliant finish medal is desired.


The Stamping Die

Read information about making the stamping die here.




Minting

The word minting is usually exchanged with striking and stamping. The minting press utilizes very high pressure (e.g. 300 tons), to impress upon the blanks a negative motive of the die. After fixing the top and bottom dies in the minting press, blanks are fed to the press and are stamped on both sides at once. If the medal is required to have a low relief then one strike is enough, however, Proof or High Relief medals may be struck two or more times. After each strike, the medal must be heat treated to reduce its hardness.


 

Two stamping (minting) steel dies used to mint the two sides of a metal blank

 

A hydraulic press used to strike blank metal disks with an impression using a minting die

 

A hydraulic press while pressing a blank metal disk. After fixing the top and bottom dies in the minting press, blanks are fed to the press and are stamped on both sides at once.

 

A blank brass disk after stamping (striking or minting) using the minting die shown above, the medal shown is after the first strike, in this case more than one strike will be required to achieve good impression

Finishing

Depending on customer requirements, different procedures are used to produce different types of medals. Minted medals can be gold plated, silver plated etc... They can be chemically treated (artificially oxidized) to give them an antique appearance, sandblasting may be required, surface polishing may be applied, even hand color-filling may be required.


 

The same minted blank above after it is surface-finished and gold-plated

 

The same medal ready to be presented


This article is also available as a file in this link

Minting Medals