Hardcore mode crafting unlocks

Since I have already unlocked the crafters, when I start a hero on normal, my blacksmith etc are already leveled up.

I noticed that when I started a Hardcore character, they are not there.

So, now that I have unlocked them on a hardcore hero, will they stay present on other hardcore heroes, and share the unlocks with the other hardcore heroes? Or will I lose all progress on the crafters when the hardcore hero dies?

Normal and hardcore modes are separated from each other. This means your hardcore characters have a shared blacksmith, but your normal characters have a different shared blacksmith.

The same applies to the auction house, because items and achievements are much harder (thus more expensive) to get in hardcore.

In short: no, hardcore and normal have separate blacksmiths/jewelers, but they are still shared within the same mode. (All your hardcore chars have the same blacksmith.)

More differences: Differences between Hardcore and Normal heroes