I hope there will be very little difference, or none. H1 is no longer being made, so when it is gone, the knives will switch to H2, from a different factory I believe. It appears that it may be more corrosion resistant, if that is even a thing. There is some concern that it may be a tiny bit softer, but we don't know that yet. Hopefully, that isn't the case, and it is very similar to H1.