4mm 4mm Long Wood Drill, Extra Lange Bohrer, HSS Twist Drill Bits with Straight Shank for Hard Metal, Stainless Steel, Cast Iron and Other Hard Materials, 1 Piece: Amazon.com: Tools & Home
Bosch 2608585869 Metal Drill Bit Hss-Co 12mmx3.98inx5.94In - - Amazon.com
kwb 4 mm Metal Drill HSS-E 248640 (Industrial Quality, Extreme Heat Resistance, for Difficult-to-Machine Materials, Precision-Ground, DIN 338) - Jobber Drill Bits - Amazon.com