If you purchase cheap dual contact tooling after being told by a supplier that it will work just as good as the original you risk unsatisfactory performance.
A pilot or spot drill, also known as a starter drill, is typically required when the succeeding drill is longer than 10xD or smaller than Ø 1.00 mm. Starter drills can also be used to improve hole location due to their short, rigid geometries.
Based on a cylindrical connection with radial locking screw, the world-famous modular precision tool system BIG KAISER has continuously been improved over the years, and has adapted to customer’s needs and the increases in machine tool performance.