Working with hard metals requires the best cobalt drill bits. We tested top picks to see which bits could bore through the toughest metals. Check out our reviews and discover which one came out on top ...

Aluminum is said to be resistant to the alum as well, but if your busted bit is buried in steel, you’re out of ... a group that would frequently break bits in brass – clockmakers.

These are robust steel drill bits, good for drilling into wood, plastic or metal. One downside: At high drill speeds, they can overheat and soften, becoming dull. This is especially common when ...