jamesmartin
Well-Known Member
cobalt are good ,but an old machinist i used to know sharpend masonary bits
Those titanium coated bits are a con, they have the thinnest coating possible on them which scratches off the moment it hits the workpiece.
A properly sharpened hss bit will do just as well, or else get a set of cobalt steel drill bits.
See post #18
Thought that post referred to a DIY sex toy.