Even just counting metric there are far too many sizes of hex bits. Adding inch sizes further complicates things, and as you say, the similarly of some of them to their metric counterparts isn’t helping; is 5/32 close enough to 4mm to not break things? Who knows!
With that said, torx is really no picnic either. T6, 8, 10, 15, 20, 25, 27, 30, and 40 all seem to be in relatively common use, and I’m not sure they all need to be. Not to mention the (relatively common) security variants of at least the 10 through 40.
I think #1 - #4 square are the only ones I’ve ever seen in the wild, though I’m informed security versions of at least #2 - #4 exist too.
Even just counting metric there are far too many sizes of hex bits. Adding inch sizes further complicates things, and as you say, the similarly of some of them to their metric counterparts isn’t helping; is 5/32 close enough to 4mm to not break things? Who knows!
With that said, torx is really no picnic either. T6, 8, 10, 15, 20, 25, 27, 30, and 40 all seem to be in relatively common use, and I’m not sure they all need to be. Not to mention the (relatively common) security variants of at least the 10 through 40.
I think #1 - #4 square are the only ones I’ve ever seen in the wild, though I’m informed security versions of at least #2 - #4 exist too.