Tighten a Loose Sword Sheath




A good katana manufacturer makes sure each sword fits securely in its saya. Despite their best efforts, sometimes a sword will be loose in its sheath or become loose over time with repeated drawings,
Shimming a saya is the prefered method for tightening a katana, wakizashi or tanto in its sheath.

You will need:
- wood veneer edging
- lighter/match
- narrow flathead screwdriver
- scissors
- your sword

Step 1: Familiarize Yourself With the Saya

Start by drawing the sword and setting the blade aside in a safe place. If you look into the mouth of the saya, you will see that the width of the opening tapers. The mune (rear) side of the blade is wider and the ha (edge) side of the blade is narrow. The shim will be applied to the ha (edge) side of the saya.

There is no need to shim the entire length of the scabbard. The blade doesn't actually contact the inside of the sheath. The only point of contact should be between the habaki (the metal collar at the base of the blade) and the saya.

Step 2: Cut the Wood Veneer Shim

Use a pair of sharp scissors or a knife to cut a piece of the wood veneer edging. The strip should be as long as the habaki and as wide as the ha (edge) side of the saya opening.

Step 3: Attach the Shim to the Saya

The wood veneer edging has a heat activated adhesive on the back. Insert the shim just inside the mouth of the saya on the ha (edge) side. Heat a narrow flathead screwdriver using a lighter, candle or other heat source. It doesn't have to be red hot - it should be around as hot as a clothing iron. Once the screwdriver has been heated, use it to apply pressure to the wood shim. After 10 seconds or so, remove the screwdriver and return the sword to its saya. Putting the blade back in the sheath is the best way to get even pressure on the shim while the adhesive sets.

Step 4: Job Complete!

After the adhesive has set, you can test the fit of the sword. It should be held firmly in place but not be difficult to draw. If it is a little too tight, it will loosen naturally over time. Avoid sanding or filing the inside of the sheath as residue could end up scratching the blade.

Traditionally, shims were fashioned of the same wood as the saya and attached with a rice paste. The wood veneer edging and its adhesive are usually soft enough to avoid damaging the blade.

This tanto was loose but now can be held upside down with no chance of slipping.



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    10 Discussions


    10 years ago on Introduction

    nice tanto. man, i wish i had the experience to make something even close to that.


    10 years ago on Introduction

    dose ANYONE know how they wrapp the diamond pattren on the handle someone please help got a website that i can go to or explaine anyone help you guys are my last resorte


    11 years ago on Introduction

    Traditionally, katanas and other japanese scabbards were glued together with rice/water paste, and the scabbard can be opened by soaking in warm water. Yours is (i believe) a chinese made sword, and the scabbard is glued with superglue.. The metal cap that keeps the scabbard from splitting can be easily removed by tapping it on a hard surface. The scabbard can then be split for cleaning (unless there is a lot of lacquer covering the 2 halves--if this is the case, you have a cheap knock-off, and you might as well have another one made or make one yourself). The glue that is most often used in chinese made katanas becomes very dry and brittle, and becomes powdery with a lot of drawing/sheathing the blade. Also, I notice the marks on the inside of the scabbard where the edge of the blade has made grooves in the metal. The spine should be the only part of the blade to be touching the lip of the scabbard.

    1 reply

    Reply 11 years ago on Introduction

    This tanto is the Musashi Asuka:

    It's by no means a top of line item. Though it's a handforged blade, the fittings are definitely not 100% traditional and historically accurate. I actually got this particular knife to cut my wedding cake - something I would never do with a high end blade. The shim technique is still useful as a cheap and easy solution that can be applied to any blades that are held in place by friction from the habaki. Cheaper swords are more likely to need shimming in the first place - plus the people reading this instructable are more likely to have mass produced swords than ones using 100% traditional techniques.