Product description AUTO-DELLO drills are made of alloy cobalt tool steel R6M5K5 Cobalt 5%. Cobalt included in the steel composition allows to maintain hardness at high temperatures, which is especially important when drilling difficult-to-machine stainless steels. - They have high wear resistance. - The tip of the drills is sharpened in a cross-shaped manner at a 135° angle, which allows drilling of high-hardness metals. - Hardness of 64-67 HRC. - Packed in an envelope with a hole for easy storage. Using drills with increased wear resistance and hardness significantly saves the time spent on drilling and simplifies the work of the car mechanic multiple times.