The classic copper book mold produces a carbon and sulfur pin and spec coin for chemical analysis. The copper book mold is a simple but effective tool that can be reused, over and over, to produce metal discs for fast and easy chemical testing. It produces a 3/16” diameter pin used for carbon analysis or sulfur analysis and a 1 5/16” diameter x 3/16” thick chilled spec coin for chemical analysis. The copper mold chills the metal to give an accurate assessment by the spectrometer giving you the most accurate information for your casting operation.