Nagakatsu saws

Nagakatsu saws are the best in the world. We have not found a saw that cuts as smoothly, tracks its own kerf so tightly, or leaves a finish as clean. No, we haven't tried every saw in the world - but neither do we want to. If we can only have one saw for the rest of our days, it will be a Nagakatsu.----

The World's Best

What could you achieve if you spent your career focused on one task? If you worked ten hours a day, six days a week, on one craft and one job, how well-honed would your skills be in ten years' time? What about twenty years' time? What about fifty?

Shoichi Nagatsu is a saw sharpener based in Kyoto. He sharpens and tunes new and used saws. That is his trade, profession and obsession. And his work is absolutely breathtaking.

There are many rules around Japanese toolmaking and woodworking - however, when you reach the level of mastery that Nagatsu-san has attained, rules become mere suggestions.

We are very happy to own a Japanese ryoba saw that Nagatsu-san has filed push-teeth into. We have heard of him filing Japanese pull-style teeth into a vintage Disston saw plate.

And we have seen him, first hand and up close, instantly improve the performance of a saw just by tapping along it's blade. He didn't touch the teeth - just the middle of the plate. The result was utterly transformative for the saw, and equally humbling for it's user. How did he do that?

The saws that are sharpened under the Nagakatsu brand - Nagatsu's maker's mark - distill the brilliance, the beauty, and the challenges that make Japanese toolmaking so astounding. In the following words, let us break it down for you.
We have now received three seperate shipments of Nagatsu-san's work over a period of two years. Not that you would know it - this is the first time we have made them live on our website. Previously we were only able to bring in limited numbers of these special saws, which we sold one by one from our Kogarah workshop or guarded jealously in sturdy boxes.

Nagatsu-san has, however, generously allocated us a double-digit number of saws in our most recent shipment, and so we are now offering them for sale here. Even then, there are caveats. Nagatsu buys the raw saw plates from his preferred suppliers before adding his teeth, and these particular plates have been waiting since the late 80s to be filed, set and honed. They are the last of that stash of saw plates, and so neither JTA, nor anyone else, will be able to restock these exact saws.

In this shipment we chose just two kinds of saw - a ryoba model, and a kataba model. Both are 240mm long. We anticipate a shipment of spined Dozukis in the future, however, as the saw plates are yet to be manufactured, we do not have a lead time.

So, what does Nagatsu-san do that makes his saws so special? The quick answer is that he sets the teeth, files them, and peens the plate. But such a quick explanation does a gross injustice to the time and skill that is invested into each one.

Peening the Plate

This is a dark art. Saw plates do not always arrive to Nagatsu-san straight and flat, and need to be hammered in to shape. However, the true purpose of peening is much more than correction - by placing pin-head sized hammer marks down the saw blade, Nagatsu introduces tension into the surrounding steel.
By adding deliberately-placed runs of them in the centre of the plate, the perimeter of the saw begins to act like a frame, containing the now-tensioned steel and making the plate stiffer and less prone to whipping around out the back of the cut.

Setting the Teeth

Nagatsu san sets every tooth with finely-tuned and highly sensitive instruments - his hand and a hammer. The run of teeth is assessed by eye, corrected if necessary, and then moved on to sharpening. The touch needed to set these teeth so well with a mere hammer tap is astounding.

Filing the teeth

Nagakatsu crosscut teeth are the most distinctive and eye-catching aspect of these saws, so let's start there.

It is worth noting off the top that none of Nagatsu-san's saws feature impulse hardened teeth. He took great pains to explain to us that the process of impulse-hardening (which most commercially available saw blades go through, whether in Japan or around the world) toughens the steel at the cost of dulling the edge. This means that the performance of the saw is compromised, as well as meaning that it cannot be resharpened.

Nagatsu-san has no patience for impulse-hardening as a process, nor for machine grinding of teeth. All of his plates feature high quality steel and hand-filed geometries.

The large gullets are cut into the plates before either of the above steps. The last tooth before each gullet is filed to rip, with the group of teeth in front of them filed in a more traditional cross-cut pattern.

This means that, once the short run of crosscut teeth has made their cut, the following rip tooth takes a shaving of the waste material. The next clump of cross-cut teeth then repeat the process.

The result is a stupendously clean cut, and a row of teeth that work beautifully well both across and with the grain. Nagatsu also incorporates this tooth pattern on his Ryoba saws with a complete rip-cut pattern on the opposite side of the plate, for those looking to do a lot of efficient ripping.

As you may be aware, cross-cut teeth require three facets to be filed per tooth, and rip-teeth two. The teeth alternate direction left and right down the plate. Every single pass of the file is made by hand with incredible consistency and immaculate patience, all judged by an eye that has literally seen more saw teeth than you have had hot dinners.

Nagatsu-san is one of the last saw sharpeners working this way in Japan. These incredible tools' manufacture is matched only by the delicate tension they emerge from, as makers of Nagatsu-san's generation retire, and their gifts are denied to the world.

Thankfully, Nagatsu has an extremely skilled apprentice, Takashi-san, who works with him. Even so, two pairs of skillful hands can only hand-file so many saw teeth in a day. We are very proud to represent their tools in Australia, and commit to facilitating a service for the owners of Nagakatsu saws to be able to have them resharpened by him in the future. With good care and careful use, these tools will last their new owner a lifetime. We hope that you take the plunge and become one such lucky woodworker.

Happy sawing,
The JTA Team

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