MOHOO 5PCS 16-30MM HSS Drill Bit Hole Saws Set Stainless High Speed Steel Metal Alloy hole drill bit Material: HSS high speed steel(hole drill bit). 5 hole drill bits Size: 16mm/0.62" , 18.5mm/0.72" , 20mm/0.78" , 25mm/0.98" , 30mm/1.18" High-speed steel and stainless steel hole drill bit, sheet metal reamer. Hole drill bit are through a special heat treatment, sharp edge, high strength. hole drill bit are with High precision, smooth cutting, especially impact resistance, wear resistance.Openings for stainless steel, iron, aluminum, and various types of pipes.