Copper tungsten (CuW) is a powder metal product designed to combine the best EDM properties of copper and tungsten. Copper tungsten combines the high electrical conductivity of copper with the high melting point of tungsten. The blend of these two metals creates an electrode material with very good wear properties. Copper tungsten is unmatched for its wear resistance and holds up very well in sharp corners. Copper tungsten is also the preferred material for EDMing carbide. Copper tungsten cannot be manufactured by conventional alloying techniques since the copper would vaporize before the tungsten began to melt. That is why copper tungsten is made by the powder metal process. Copper and tungsten powder are pressed into a preform and then sintered. During sintering, the material shrinks by approximately 25% and great care must be taken to avoid porosity, which is a common defect in copper tungsten electrodes. A porous spot will leave a bump in the EDM cavity. SST Consumables only sells copper tungsten made by the Press-Sinter-Infiltrate process which virtually eliminates porosity.