Extending the Life of the Shinai (竹刀)

This a brief article on some ways to help extend the life of the shinai (the bamboo sword) for the beginners at the dojo I practice at and all who find that their shinai‘s do not last long.   I present a short version and a long version.

Updated:  Nov 21, 2021 with two figures.

Short version

Store them in places with humidity, hit properly (e.g. striking the top of the men rather than the metal grill of the opponent, with the proper part of the shinai and with sae (sharpness) ) and perform shinai maintenance.

Long version

Here are some ways extending the life of the shinai.  I list them starting with those with greater effectiveness for me.

  1. Storing them in a place with moisture.
    1. Some years ago, I bought a set of rather pricey shinai‘s only to have each splinter and break after roughly one to two months of usage.  Looking back, I think the reason for their short life-spans had to do with dryness – which comes with the climate of Southern California.  I had left the shinai‘s in a dry place.  Furthermore, it didn’t help that they had been stored in a warehouse that may have also been very dry – when I purchased them.  After that experience and hearing how others took care of their shinai‘s, I began storing them in places with moisture – near the washroom and kitchen.  Now they last much longer!
    2. This shouldn’t come as a surprise to me.  Years ago when I practiced in Japan where it can be very humid and practices were much more frequent, a shinai would last for at least 6 months to a year.  I rarely needed to buy a shinai then.
  2. Striking “properly.”
    1. It is possible that I may be striking the men in a manner that the shinai now approves of and likes.  More with or closer to the ken-saki (tip) of the shinai (away from the naka-yui (the leather strip which wraps around the shinai several times) ) – rather than closer to or below the naka-yui.
  3. Blunting the sharp edges of the shinai slats.
    1. My senpai‘s taught me to make the somewhat sharp edges of the shinai slats more blunt as illustrated in Fig. 1 below for a single slat of the shinai and in Fig. 2 for the four slats of the shinai.
      1. This allows the shinai to flex more easily and removes the sharp edges which could splinter.
    2. This can be done by sanding the edges down (and oiling the sanded areas afterwards) or pushing a large beer bottle against the edges.
  4. Maintaining the shinai.
    1. I’d suggest watching this video:  Paul Shin, “How to Maintain a Kendo Shinai” – (18:23 mins)
Fig. 1 The before and after image of the cross-section of a single slat of the shinai with its edges rounded out.


Fig. 2. The before and after image of the cross-section of the four slats of the shinai with its edges rounded out.

May your shinai‘s last longer! 🙂


Copyright 2021 KendoNotes.com

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