Review on Bosch CO2135 2-3 Cobalt Drill Bit by Adam Matthews

I've only tested it a few times on thick angle steel and once on stainless steel, but no sign of dulling. He pierced it like butter after my cheap port cargo drill just sat on the surface making a hot groove instead of a hole. I've used cutting fluid (WD-40 or water if you don't have cutting fluid on hand) and I always recommend using cutting fluid and also cooling off any smoke or smell of hot metal/fluids. Getting the drill too hot is the best way to ruin it, let alone use it as a tool. I drilled a stainless steel yoke that my cheap titanium coated bits didn't even make a dent in. excellent, and the racquet definitely cuts hardened steel like a champ. I will use them for drilling light holes and whatever else I need. I haven't checked for dimensional accuracy, but it has no visible flexing or wobbling. I'll say it goes around and doesn't start where I want it to unless I use a middle hit. This isn't a problem for me as I usually use a spring loaded center punch, but I've noticed that some bits travel more than others. I'd say this one goes a little longer than the cheap, soft ones, but once it starts biting it goes right through your steel. I will be ordering some of these in regular sizes which I tap for 5/16", 1/4", 3/8", 4mm, 6mm, 8mm. Not sure what this brand is offers in metric sizes, but I take a look Disclaimer: I'm not a machinist or a drill, I'm just a hobbyist who does a lot of home, RV, jeep and motorcycle repairs.