Investment Casting Process we used here are lost wax casting, are always classified in 2 types, one we called here is an American style silicacel process with green wax (median-temperature wax) and better sand, with very smooth surface, tight tolerance, suitable for small part making widely used for stainless steel, carbon steel. It's different with an Russian style investment casting actually called soluble glass process with white wax (low-temperature wax ) and rough sand with relative rough surface, bigger tolerance, suitable for large part making more than 1.00KGS especially for carbon steel