Precise hsssc offers a liquid cooled drilling spindle, model sc-52. Solid-state frequency converters drives 2- or 3-phase spindles. These compact units are particularly economical because, extremely quiet running, minimal speed variation under load and the employment of modern cutting tool materials machining cycles can be drastically shortened due to their high speeds. The ball-bearing mounted high frequency precision spindles are used principally in pcb production. These are suitable for precision machining operation on ferrous and other metals due to their excellent rigidity. All spindles in this series are equipped for use with atc system with direct tool shank chucking. The tool shank is situated directly in the collet. This represents an economical, precise improvement on conventional atc tool holders. New requirement in cutting technology have led to the development of this series [sc2] having spindle speed up to 60,000 rpm. This precise high-speed spindle attains the ideal cutting speed especially on smaller tool diameter and modern efficient cutting materials like cbn, pcd, pcb, etc. High quality machine tools are equipped with precise spindles for precision drilling, which results in economical high quality production.