Cobalt steel tools are similar to high-speed steel, but with more cobalt for improved performance when cutting harder metals such as stainless steel or nickel alloys. Gold oxide is a thinner oxide surface treatment than black oxide typically used to identify cobalt steel tools; performance is similar to uncoated tools. Round shanks allow use with a wide variety of toolholding systems. When run in a counterclockwise direction (right-hand cut) spiral fluted tools evacuate chips up and out of the cut to reduce clogging. Ideal for portable or machine drilling.
They advertise these cobalt drills with the screw length, they are SIGNIFICANTLY longer (longer) and very carelessly carved, burrs, burn and cut marks are all still available there. None of these drills were straight either. Terrible waste of time.
My drill bit only has a 1/2" shank so it didn't work for me. I offered it for free to a neighbor who does industrial work and he also doesn't use a shank larger than 1/2 inch. So now I have a really good piece that I doubt I'll ever use unless I buy a 3/4" shank drill press.
I confess that I bought them specifically to use them under high downtime conditions. That's why the shorter length was so attractive. Using a hand drill, drill out the large aluminum rivets that held the steel and aluminum panels together. I was fully prepared to break the bits and chip the cutting edges. Guess I did all the work on the first shot. Will you be just as lucky? I do not know. Maybe my experience with metal saved the beats? However, I was so impressed that I bought other sizes toβ¦