Amazon.com: ASNOMY 7PCS TCT Hole Saw Kit for Metal, 16-30mm Tungsten Carbide Tipped Hole Saw Hole Cutter Drill Bit with Titanium-Plated Pilot Drill bit for Hard Metal, Stainless Steel, Iron, Wood, Plastic :
Bosch 2608585884 Metal Drill Bit Hss-Co 4, 8mmx52mmx3.39In 10 Pcs - - Amazon .com
Hitachi 752082 ZKBF Drill Chuck 10 mm and Hex Adapter 1/4 inch - - Amazon .com
5 pieces diameter 3.5 mm HSS Co 5% cobalt spiral drill/metal drill bit DIN 338 – drill / steel drill 135° point angle and split point : Amazon.de: DIY & Tools