1、Multi Purpose: Drill bit is suitable for iron aluminum copper, stainless steel, high speed steel, manganese steel, all kinds of quenched steel. 2、Fast Drilling: 24mm drill bit adopts spiral chip removal design, smoother chip removal, smoother and incisive slot, fast cutting, high drilling efficiency. 3、High Accuracy: Black twisting drill adopts 118° incisive angle design, fast and accurate drilling, saving time and effort, and improving work efficiency. 4、Excellent Material: Small shank drill bits are made of high quality high speed steel, with high hardness, stable performance, sharpness and durability. 5、Practical Durable: Straight shank twisting drill has a finely ground and incisive edge to meet different cutting precisions. It is very sturdy and practical.