Dwarven Blacksmiths give a piece of their mind on medieval Japanese steel
2Japanese sword blacksmiths were highly skilled and came up with many ingenious swordmaking techniques to make their katana. Due to lack of their technological ability to make a furnace of over 800°C whereas iron completely separates from impurities at around 1000°C. They came up with the idea of folding the bloomery pig iron in order to even out the impurities throughout the blade to prevent one part of the blade from being weaker than the rest. The cutting side is harder carbon steel while the back side is soft core steel in order to make it flexible. After all being hard came with the downside of being brittle as well.
However, no matter the indigenous techniques, lack of high quality steel and 1000°C furnace technology can still be seen due to how Europeans could afford to make way longer but lighter swords which is completely hard on all sides. They could also make incredibly thin and long but still strong swords which were incredibly flexible. Japanese katanas could not afford to be thin because it would mean missing out on either its soft inner core or the hard outer core. And Japanese katanas of same weight than an european longswords were incredibly shorter in comparison due to their unreducible thickness. And they were still prone to shattering despite the shock absorbing soft core, something which european swords neither needed or did they shatter. One can only imagine what ingenious swords could the japanese swordsmiths have made with the european quality steel and 1000°C temperature furnaces instead of being limited to pig iron and 800°C tatara furnace.