Driak 6 pcs Carbide Tip HSS Twist Drill Bit Set for Stainless Steel Metal Cutter ,12/14/17/18.5/20/22mm Hole Saw Drill Bit Set High Speed Holesaw Round Twist Cutter Tool Hole saws & Adaptors Sharp Blade and High Strength High precision,smooth and steady,shock resistance,abrasive resistance Cutting of ferrous, nonferrous metal effect is excellent.Can work for 4mm Stainless steel plate