Steel can be pretty difficult to drill with a hand drill, but with a sharp bit, a proper pilot divot, and some cutting fluid of some sort (old timers used bacon grease - still a great cutting fluid, even when it goes rancid).
The main key with metals (and heck, even with wood and certain plastics) is to have in place the pilot divot, so the bit doesn't wander. People seem to have the most trouble when they don't do this part first. Sharp drill bits are also very important. You usually only need a cutting fluid on steel.
Also - aluminum is almost as easy to drill as wood. Just add a good divot of course, and go for it. Some light 3-in-1 oil can serve as a mild cutting fluid. It isn't really needed, but it can be useful to keep the chips from flying everywhere (not as big a deal though when hand drilling).
Another easy to drill material is HDPE (cutting board plastic). Cuts and drills like soft wood, just don't get too aggressive with speed (especially when cutting - as it can heat up, melt, bind the blade, or self-weld behind the cut).
The main key with metals (and heck, even with wood and certain plastics) is to have in place the pilot divot, so the bit doesn't wander. People seem to have the most trouble when they don't do this part first. Sharp drill bits are also very important. You usually only need a cutting fluid on steel.
Also - aluminum is almost as easy to drill as wood. Just add a good divot of course, and go for it. Some light 3-in-1 oil can serve as a mild cutting fluid. It isn't really needed, but it can be useful to keep the chips from flying everywhere (not as big a deal though when hand drilling).
Another easy to drill material is HDPE (cutting board plastic). Cuts and drills like soft wood, just don't get too aggressive with speed (especially when cutting - as it can heat up, melt, bind the blade, or self-weld behind the cut).