The sets include high-performance tools with a countersink angle of 90 for countersinking 90 screws for particularly tough and hard materials such as alloyed and high-strength steel and stainless steel (INOX). 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. Long tool life and temperature-resistant version due to Co content. The sturdy plastic box protects the tools against dirt and damage.