Hi All, The weight of some swords should show differences in weight due to the niku of the blade, given other dimensions were equal, which changed over time like much of the other characteristics of specific periods and schools. What elements are in the steel will affect the weight as well, but most nihonto would have had similar alloy content, carbon and iron. Some nambantetsu made have different components but would not affect much noticable weight difference. Modern shinken can have a larger range of density due to what alloy it was made with. eg. steel 7850 kg/m3, stainless steel 7480 to 8000 kg/m3 or relative density 7.75 to 8.05, mild steel at 7.85 weighs 0.283 lb/in3 John