The sets include high-performance tools with a countersink angle of 90 for countersinking 90 screws for all common materials such as steel, cast steel and non-ferrous metals. Conical countersinks with unequal pitch (UGT) are characterized by a specially developed geometry with wide flutes, which enables optimal chip removal and heat dissipation, smooth running and optimum results. The sturdy plastic box protects the tools against dirt and damage.