One Piece Episode 410

[Assertn]

Isn't that exactly what Zoro's master was talking about?

http://www.onemanga.com/One_Piece/194/15/
http://www.onemanga.com/One_Piece/194/16/

Zoro says he "transfers his thoughts through his sword" here:
http://www.onemanga.com/One_Piece/195/18/

Now you're just drawing assumptions. There's no significant correlation between cutting steel and having a sword imbued with haki.

Just like how there's no significant correlation to say, Luffy's gear 2nd vs Soru.