[sdiy] What is the name of this tool?

[Jason Tribbeck]

Hi,

> I was wondering: can stepped drills actually drill the 
> initial hole or do you need to pre-drill those with something else?
> As I see some of them have a flat tip...

I use them to drill the initial hole sometimes - although it's better if
you're only using them for thin panels. If they've got a flat tip,
though, they're probably not suitable for this.

If it's a large size, though, it's worth using a different drill to do
the initial hole as it'll save wear on the stepped drill bits.

What I found was that I was drilling 13mm with my normal drill bit and
it'd be the 14mm part of the stepped drill that suffered the most (but
after removing the stuff that built up on it, it was fine).

I also use them for de-burring holes as well (twisting them by hand).
--
Jason Tribbeck