What is the difference between hubs D462SB and D162SB? They look the same to me.
Yes, the very first impression you get is that indicated hubs look almost identical and reason for that similarity is because they both have the same hub shell. But main difference is in their inner construction.
Hub D162SB is more economical hub and it comes with steel axle and steel cassette body which are both mounted together as one whole.
So if you want to convert you hub from one axle size to another, you need to buy such axle along with cassette body as one spare part.
Picture below clearly illustrates what I mean:
Hub D462SB is convertible hub supporting multi-axle system which comes with separate cassette body (alloy or steel) and separate axle + side cap. Conversion to different axle size is easy, you just use the adapter (axle + side cap) to desired size.
Picture below shows the correct type of cassette body for mentioned hub: