Why am I able to do highest quality blacksmithing in case of axe, but struggle completely in case of swords

[Hochmeister]

Are swords less forgiving or what? It seems to me, that eventhough I do big swings, try to keep it yellow hot, I only sometimes get the sparks from smashing. It's really strange, that I don't have this issue with axes and hunting swords.

[Ruck]

I've not noticed much difference in the difficulty between forging axes and swords. Swords actually seem a bit easier since your hammer stays on rails for the most part and always hits the blade.

I think there is a certain reforged sword that can't be made into a Henry quality sword, but any other kind of common sword should easily hit the 4th tier once you've got the perk for it. There is a bug where sometimes the pop-up after crafting shows a lower tier, but the item in your inventory is actually T4. Double check your bag to make sure that's not what's happening.

Another thing you can do if your craftsman skill is a bit low, wear the blacksmithing apron and a pair of leather gloves. This gives a hidden bonus of +5 to craftsman skill which could help if you're just barely missing the T4 quality threshold.

If you're really having a lot of difficulty and are sure you're doing it right, here's a way to cheese the entire minigame. Apparently it's not nearly as strict as the game indicates:
https://old.reddit.com/r/kingdomcome/comments/1iz5zvj/kcd2_psa_smithing_is_not_as_deep_as_the_game/