From wikipedia:

“ Paul Pelliot saw that the tradition according to which Genghis was a blacksmith was unfounded though well established by the middle of the 13th century.[27]”

It seems at least the concept of blacksmiths was familiar to the Mongols before or around the time they went into china.

Thats why I explicitly stated “steelworking” instead of “ironworking”. Although they couldnt do it in large quantities the common European smith could use it to enhance his iron products[1]

Whereas even the quality of the steel used by the experts in China (even by the 1600s) is questionable. [2]

[1] https://the-orb.arlima.net/encyclop/culture/scitech/iron_ste...

[2] https://www.tf.uni-kiel.de/matwis/amat/iss/kap_a/advanced/aa...