PCD ( Polycrystalline Diamond) is manufactured by sintering micron size diamond particles ( typically 10 micron ) to form a solid large intergrown mass of diamond suitable for cutting tool elements , wire drawing dies and wear part surfaces. It is normally bonded to a tungsten carbide substrate to enable manufacturers to bond the PCD to toolholding systems. 
 

Since it's introduction in the early 1970's the use of polycrystalline diamond has grown dramatically. Initially the use of PCD was restricted due to the limiting size of the raw material. Advances in diamond synthesis technology have increased the size of polycrystalline diamond disks from approximately ½ inch (12.7mm.) in diameter to a massive 3 inches (74mm.) in diameter.
 

Advances in technology have also led to a proliferation of formats, grades and configurations for PCD disks. Demanding applications such as the machining of MMC's (Metal matrix composites) are now possible because of this. There are fine grain materials that provide excellent edge quality and workpiece surface finish while coarse grain products offer superior wear resistance.