Product description. Set of universal metal drill bits by STHOR 22640. Made of durable and high-speed HSS steel. Allow you to make precise holes in hard alloy steels, aluminum, sheet metal and PVC. - Titanium nitride-coated surface - tapered profile for easy drilling and centering - edges of drilled holes remain clean and burr-free - included: reamer, tapered countersink, step drill and milling drill. Parameters. Material: HSS. Application: Metal. Grip: Walled.