Buy a set of hex shank sockets and you're done with a set of drill bits like this one .No need to carry two drill bits.Put in a drill bit and quickly change it to a head to tighten the screw.These bits are made of titanium so they can cut even hardened metals,but also do a good job with wood afford. different bit sizes for each of them. As instructed in the instructions, when drilling, use oil or grease to keep the drill bit cool and do not drill at an angle to avoid breaking the drill bit. Once you get to the Once you get used to bits, that little breakage becomes a constant problem, so it's handy to have a spare set like this in a smaller size to catch up on larger sets ufill. Highly recommended.