Simply buy Centre drill HSS-E A uncoated | Hoffmann Group
Alpen Cobalt HSS Spiral Drill Bit for Stainless Steel and Stainless Steel extrakurz DIN 1897 Cylinder Lock Diameter 6 mm Length 66 mm. 28 mm, 92100600100 : Amazon.de: DIY & Tools
HSS Stuff 42O Alternative Colour Variation : Amazon.de: Garden
Projahn Twist Drill Cassette Turbo (19 Pieces, with Cylindrical Shaft, Ground from Solid, Long Life, Each 1 Diameter 1 - 10 mm Increments 0.5) 60314 : Amazon.de: DIY & Tools