MATERIALS
DESIGN
MANUFACTURE
MAKING YOUR OWN SHURIKEN
Traditionally,
shuriken were fashioned from pre-existing metal implements, rather than
being specially made to design, a fact which quite probably greatly influenced
the overall shape of blades within each particular style. In pre-Meiji Japan,
metal was scarce and its use devoted predominantly to conventional weaponry, (swords
in particular). Metal smelting technology was imported to Japan from China via
Korea around the 8th Century, and refined over the subsequent millenium. Japan
was not a great source of iron ore, so what little they did have of the low grade
satetsu, or "iron-sand" required a lengthy and ingenious smelting
process (called tatara), which produced a black slag of varying (and low)
carbon content, called tamahagane. This product was a black, rough pig-iron
that needed further refinement to become the great swords Japan is famous for.
One may notice that many older metal weapons, such as shuriken, jutte,
manriki-gusari, as well as many other metal implements such as furniture
fittings, all exhibit a rough, matte black appearance. The metal was heavy, easy
to work with, and relatively easier than the sword metal to produce, however it
suffered in hardness and tensile strength. I guess that is why this Ikkyu Ryu
shuriken example #5 has broken points.
I have heard that specific construction methods, particularly in the Negishi Ryu, have been kept secret, and since there appears to be no historical documents extant today on subject, this information remains unclear. Micheal Finn, in his 1983 book 'Art of Shuriken Jutsu" writes that shuriken were fashioned in a similar way to that of Japanese swords, ie. they were folded and hammered over a furnace, however I am yet to confirm this.
Since shuriken were fashioned not by design, but by opportunity from pre-existing metal ware, it seems that what was required was a cheap and easy-to-make weapon, one that appeared harmless in that it looked like either a tool, construction or carpentry implement; crude, simple and dispensable. Nowadays, there is a great variety of metals produced, each with varying combinations of physical properties such as hardness, tensile strength, heat resistance and conductivity etc.. So rather than attempt to imitate the traditional blade to the point that we use exactly the same metal, the spirit of the art requires that we use whatever is cheaply, practically and effectively available to us. For this reason, I think it proper to search for everday items which can, with little effort, be adapted to create a throwing and piercing weapon that can be concealed in the palm. Providing that it follows the principles defined by the art which determine their use, such as size, shape, balance etc., the source of the metal for the shuriken is of secondary importance.
Objects such as 8 inch railway nails, old carpenters files, chisel blades etc., can all be easily obtained, easily worked into shape, and yet provide an excellent source of metal, far superior to the pig-iron traditionally used for such things. Grinding, polishing and heat treating technology is more efficient and available to us these days, so why not use a bench grinder and a gas torch to achieve what the Japanese were striving to create?
