Guntō

Guntō (軍刀^?, military sword) is the name used to describe Japanese swords produced for use by the Japanese army and navy after the end of the samurai era in 1868. In the following era (Meiji Period 1868-1912) samurai armour, weapons and ideals were gradually replaced with western influenced uniforms, weapons and tactics. Japan developed a conscription military in 1872 and the samurai lost the status they held for hundreds of years as the protectors of Japan. Mass-produced guntō swords became standard equipment in the new military, taking the place of the swords worn by the samurai class during the feudal era.

During the Meiji Period, the samurai class was gradually disbanded, and the Haitōrei Edict in 1876 forbade the carrying of swords in public except for certain individuals such as former samurai lords (daimyo), the military and police. Skilled swordsmiths had trouble making a living during this period as Japan modernized its military and many swordsmiths started making other items such as cutlery. Military action by Japan in China and Russia during the Meiji period helped revive the manufacture of swords and in the Shōwa Period (1926-1989) before and during World War II swords were once again produced on a large scale.

During the pre World War II military buildup and throughout the war, all Japanese officers were required to wear a sword. Traditionally made swords were produced during this period but, in order to supply such large numbers of swords, blacksmiths with little or no knowledge of traditional Japanese sword manufacture were recruited. In addition, supplies of the type of Japanese steel (tamahagane) used for sword making were limited so several other types of steel were substituted. Shortcuts in forging were also taken, such as the use of power hammers and tempering the blade in oil rather than hand forging and water tempering; these measures created swords without the usual characteristics associated with Japanese swords. The non traditionally made swords from this period are called "Showato" and in 1937 the Japanese government started requiring the use of special stamps on the tang to distinguish these swords from traditionally made swords. During this wartime period antique swords from older time periods were remounted for use in military mounts. Presently in Japan Showato are not considered to be true Japanese swords and they can be confiscated; outside Japan they are collected as historical artifacts.

...
Wikipedia