Review on 🔩 High-performance 4-Pack Cobalt Drill Bits by TopLine by Todd Vesci

These drills should be made from M42 Cobalt High Speed Steel. I was drilling in cast iron with a #7 drill bit for a 1/4-20 screw and the drill bit hooked and twisted, twisted. I've had drill bits that break, snap or just wear out, but never one has turned like a piece of liquorice!