Product Description AUTO-DELLO drills are made of alloyed cobalt tool steel Р6М5К5 Cobalt 5%. Cobalt in the steel composition allows maintaining hardness at high temperatures, which is especially important when drilling hard-to-machine stainless steels. - They have high wear resistance. - The drill bit tips are cross-shaped sharpened at an angle of 135°, which allows drilling high-hardness metals. - Hardness is 64-67 HRC. - Packed in an envelope with a hole for convenient storage. Using high wear-resistant and hard drills allows significant time savings for drilling and greatly simplifies the work for the auto mechanic.