Product description AUTO PARTS drills are made of alloyed 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 hard-to-process stainless steels. - They have high wear resistance. - The tip of the drills is sharpened in a cross shape at an angle of 135°, which allows drilling of high hardness metals. - Hardness is 64-67 HRC. - Packed in an envelope with a hole for convenient storage. Using high-wear and high-hardness drills significantly saves time spent on drilling and greatly simplifies the work for the car mechanic.