Choosing my first set of drill bits...

[RaisedByWolves]

Not specifically mentioned in this thread but the main advantage to cobalt is that it will tolerate a greater temperature before it softens and looses an edge. With regular HSS, if you get it overheated for a millisecond it is toast.

Drillbits are not HSS, they have something in them that imparts a property known as "Red hardness", its literally the one type of steel that wont anneal due to being heated.

I turned one purple the other day putting the angles back where they belong on the belt sander.

Dont know who the last person to grind that one was, but lips were ovoid shaped.

 

[Liljoebrshooter]

Drill bits are high speed steel.
Joe