is drilled iwth light pressure, a work-hardened skin forms that is tough to get through.

Also, go to an industrial supply house or good toolstore and buy a quart of drilling fluid for stainless. Drip that on while working. that helps, although it can be a bit messy, specially on teak.

And of course as someonelse e;se saod. start small. I start with 1/8" or so, and go up in about 1/8" increments if drilling by hand.

Set drill to slowest speed you can. A few hundred rpm is plenty. Using a 1/2" gun can be good for this, since they are usually slower than the 3/8" ones and havebetter chucks