Review on High-Performance Metric Cobalt Twist Stainless Drill Set - 1.5mm to 6.5mm by David Pirlet

I bought these drills because I needed to refine my choice of metric units but didn't want to mess with one of the extremely expensive big brands. until I get a feel for which sizes I need more than others (replacing each as needed). However, after drilling many holes in hard iron with a 5mm bit and then punching a series of 77 concentric holes through a 1" thick steel plate with a 9.5mm bit (after using it to drill threaded holes in tool steel ), I am reselling you.The 9.5mm is still sharp enough after subjecting it to some abuse - I accelerated the feed rate and the number of holes drilled in succession as I worked my way around the ring until halfway through the chips turned blue. , very heavy lifts, which I'll come back to.