Professional Quality Cobalt Metal Drill Bit Set Hole Saw. Working length 1.5 cm HSS drill bits for Cobalt Steel, high speed steel 5% cobalt, very resistant. Drill bits for steel, aluminum, plastic materials Set of 5 hole saws. Diameter: 16 mm, 18.5 mm, 20 mm, 25 mm, 30 mm Application: steel, aluminum, plastic Quality Drill Bits Drill bits and hole saws specially designed for hard materials with high speed steel (HSS) with cobalt alloy. The result is robust hole saws for versatile materials and applications. For sawing holes with a diameter of 16 to 30 mm in steel, metal, placo, plastic! For use on: Stainless steel Alloy steel Metal Placoplatre Plastic hole saw set cobalt metal drill bits Improved cutting performance Correct use: Position the center drill bit in the correct place and start slowly and at a low speed. Hold the drill perpendicular to the workpiece Use cutting oil. hole saw set cobalt metal drill bits The set consists of 5 hole saws with respective Allen key for