pic: A "Bit" of a problem.

[Tristan Lall]

Originally Posted by Cory

Yeah it's not titanium. It's called Titanium Nitride coating. Helps with lubricity. Actually doesn't work all that well in Aluminum, from everything I've read (it doesn't resist chip welding in aluminum real well, apparently).

Any drill you might commonly come across will be made out of either High Speed Steel, Cobalt, or Carbide.

Cory nailed it—those bits, while decent, are just conventional high speed steel (HSS) inside. The bottom line is that it's misleading advertising calling them titanium bits. They're no more titanium bits than they are nitrogen bits, yet you don't see anyone calling them that, do you?

Though the TiN (titanium nitride) coating isn't the greatest for aluminum and titanium, it does resist abuse rather well, and the pilot points are rather useful, so those DeWalt sets aren't a bad choice for FIRST use.

You might be able to find TiCN (titanium carbon nitride) or TiAlN (titanium aluminum nitride) coatings that are more durable, and provide a little better performance in aluminum and titanium. TiCN and TiAln are actually more common on fancy endmills, than on drill bits, though. Even a black oxide coating is better than TiN, if you're only concerned with drilling aluminum (it won't stick as much to the chips).

In any event, $7.00 for that bit doesn't make sense. For example, McMaster-Carr sells something broadly equivalent for $2.61. (Look at their online catalogue to see the selection of drills that you could use instead.) Check your phone book for a machine tooling supplier or industrial hardware store in your area; they'll be able to find you something better.

Originally Posted by ebarker

Okay so is there any chance they drilled the hole with the bit turning BACKWARDS ? I've actually seen someone do that and melted a hole in an aluminum sheet.

Homemade friction stir welding?