Its actually useful to know what size hole your considering. If its something the diameter of a 13 amp cable then a good tungsten carbide bit will be ok. If its for piping etc then you'll need a diamond tipped bit which looks like a tube.
A titanium or cobalt drill bit.
Coated carbide is the best. Uncoated is next.
Use a brand-new bit for metal mounted on a hand drill (not electric). Slowly rotate the bit in the lead, which is a "soft" metal.
A standard HSS drill bit, slow it down from normal drilling speed.
It is just one of the best drill bits for drilling in the Oil & gas industry. A drill bit is basically the bit on the end of the drill that does the cutting. A premium drill bit is one that is used in really tough applications.
Diamond Core Drill Bits are the best for concrete.
cobolt
You need a diamond tipped bit to drill almost any rock.
metal drill bit has a finer point
The precise shape and angles of a drill bit.
A tungsten coated drill bit.
You need a diamond tipped drill bit to drill glass or tile.