The sets include high-performance countersink 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). Thanks to the HICOAT coating HC-FEP, they have high hardness and wear resistance. They are very temperature resistant and have a particularly long tool life. They can also be used in a higher cutting speed range and without coolants and lubricants. The sturdy plastic box protects the tools from dirt and damage.