Well his swords are more important to him than his body, especially for a swordsman going by Mihawk's statement
No doubt his blade is also durable, however, since he checked his blades after dissecting Pica, it implies that without haki, his blades would've chipped etc.
We know BC is sharp enough to cut meteors almost the size as half or more of golem Pica. However, when Zoro applied enough force to cause a shockwave in blocking the BC, there was no chipping of his swords which means his haki held up.