This drill set has a sharp cutting edge that makes it easy to cut through. Difficult-to-cut materials such as stainless steel and titanium alloy hard steel. 1.0-10.0/(0.1 increments). 10.5-13.0/(0.5 increments). 10.9 11.9 12.9. Set quantity (pieces): 100. Cobalt High Speed?? Steel (HSCO-M42). About Us: We are specialized store in Japanese Tool brand. Ninja Tools.