Replaceable blade saws.

As part of the series of essays about Japanese woodworking tools, the next step is replaceable blade saws. In order to understand the hows and whys of their development and why “they are what they are”, I’ll give you a quick explanation of how they came about and why they are so popular here and abroad.

First, some history…

Traditionally, Japanese saws were all hand made, able to be sharpened and not too dissimilar to their Western brethren in use. Yes, they were used in different ways and looked very different, but the idea of buying a saw, using it and maintaining it was common to all saw styles.

After WWII, significant changes to Japan occurred. This is not news, but the depth of change was so great that very few of the old ways were left untouched, and this affected every part of Japan as a country, culture and people.

In regard to woodworking tools, a significant change in saw construction took place, more than for any other woodworking tool. Due in part to the new abundance of steel, in part to the requirement that any tool should be used more than maintained and also that the highly skilled metate (Saw blade repairer/sharpener) and saw makers were not up to the task of producing and maintaining the huge number of saws that would be required to rebuild and rehouse the nation of Japan.

The influx of ideas and materials from outside of Japan as well as specialised machinery for milling and preparing wood also reduced the market for traditional saws to those that would be used by carpenters and cabinet makers, effectively wiping out a significant segment of the market. To add to the problem, many highly skilled craftsmen simply did not live through the war, or were unable to return to their original trade.

In short, the traditional Japanese saw’s days were numbered through no fault of it’s own other than being a very complicated piece of equipment that could be replaced with something a little more pedestrian.

Something that was easily mass produced, worked effectively and could be ‘maintained’ with minimum effort was sorely needed.

Make the saw more durable or make it easier to dispose of?

I think that the ultimate answer is fairly obvious…

The first ‘disposable’ saws.

Initially, the entire saw was considered expendable once it no longer worked. Simply making a saw in the traditional manner from less expensive materials and with less attention to detail was ‘the easy way out’. It should be obvious that a cheaply made saw is exactly that, and these saws were not really ‘effective’.

These saws can still be found today, and I can tell you from experience that I am not surprised they did not really take off. Whether made entirely by machine or partially by hand, the fact they are made to a price is glaringly obvious.

Demand required that a better solution be found, and the idea of making the blade and handle into separate units, independently replaceable was born. Obvious to us now, but at the time a king’s ransom awaited the person who could make this simple idea into a reality.

Evolution of the ‘new’ saws.

Making the saw blade easily replaceable was not such a simple task. Because the friction method of joining blade to handle added no weight and was inherently simple, a method of making this joint easily broken without affecting the long term integrity of the joint meant that the joint had to be simple, light in weight and long lasting.

The idea of placing a hard, durable insert into the handle to accept the blade was an obvious idea, and then using a common set screw to secure the blade sealed the deal. By minimising the insert’s size and mass, the balance could be maintained and the excess weight placed at the centre of gravity. The screw could be small, since it was only there to secure the blade and the load on the screw was not in friction, but shear.
An easy, simple method of attaching the easily replaced blade to a longer lasting handle was born and things started looking up.
(As a side note, this simple method of attaching the blade to the handle is still one of the most common methods of attachment, used by the majority of replaceable blade saw makers. Only the bespoke Z Saw (and others) ‘hook’ and Gyokucho ryoba methods of blade attachment are relatively common. Other methods do exist, but they are not in wide circulation.)

Making a better blade.

Now that one of the major problems had been solved, that of connecting blade to handle, the other big task was to mass produce blades of a quality and price that could best take advantage of the new idea.

The problems of making a high quality, yet low priced blade are that the steel must be up to the task, the teeth in the saw should be correctly shaped to allow cuts similar to a high grade saw but can be made by machine and the blades must be consistent.

With the influx of new technologies as well as home grown metallurgical knowledge, a suitable steel was a fairly simple task. Simply put, a steel that was tough but would retain it’s edge for a goodly time was required.

A steel already existed, that being plain carbon steel.

Now that the steel problem was addressed, how do you make saw blades quickly and cheaply?

This is where the rapid evolution of Japanese manufacturing prowess came to the rescue.

A saw blade, regardless of what style it is, is little more than an amalgamation of angles on the edge of a steel plate, which for a machine is a fairly easy task. All you need to do is make a machine that will cut each facet of each tooth, and a way to move the saw along so that your tooth cutting machine can do what it does again and again and again.

Originally, the machines made to perform this task were rather crude, but they did produce blades that worked well enough and were cheap to produce. Better saws were ‘touched up’ by a craftsman before being sent out to work, which added to the cost of production, but yielded a superior saw.

Over time, the quality of the blades the machines produced became better, and the number of saws fine tuned by hand decreased, as did the number of saws produced entirely by hand.

But the machine made saws still had an Achilles heel, and that was that the machines were expensive, could usually only make a few different types of saw and they were producing something that worked well, but were still not as good as a ‘proper’ saw and stayed sharp for no longer than a regular, resharpenable saw.

The machine made saw folks went back to work, dreaming up ways to improve their product, and this is where the wide range of saw manufacturers begin to diverge in their principles.

Some sought to reduce the cost of the saws, and succeeded to some extent, except those who chose this path and stuck to it’s principles fiercely no longer exist.

Others took the old idea of improving the saw by hand and made it new again, by offering a saw that offered improved performance for a price. Of those who chose this route, many still exist today and offer more choices than ever before.

Of those manufacturers left, they chose to improve the product AND reduce the costs. Those who chose this way, now own the market to a certain extent.

While the outright performance of the saws was not significantly improved, the longevity of the saws was. By making the tips of the tooth extremely hard, the life of the saws were greatly increased. By treating the blade with a protective coating, the possibility of rust was reduced, which was attractive to those who did not take great care of their tools.

The price attached to these improvements was relatively low, which in turn made the saws even cheaper.

Over time, these treatments filtered down and became even cheaper to implement, so now it is very difficult to find a replaceable blade saw that does not have one or both (or more treatments) applied to it.

This regimen of continual improvement also allowed a certain freedom to those manufacturers at the leading edge of the field. They had the capital to explore new areas where they could offer more in their products, with more features, more choices or new products never before conceived and impossible to implement without these new technologies.

Technologies borrowed from other fields that could be applied to saws also helped to allow manufacturers offer more products or control costs.

Things like new coatings, new steel materials, new treatments for rust resistance or improved longevity. More accurate and flexible machines allowing for increasingly complex saws, and fine tuned to a particular task.

Where to from here?

The catalogues from companies that produce saws vary from a page or two into thick catalogues with dozens of variants for cutting all manner of materials in all manner of sizes. There would seem to be little left to improve upon, and even less left to invent.

But new saws still appear, with varying success.

What is most true now that there is a replaceable blade saw for any budget, for cutting any material and with features to appeal to almost any craftsperson (or even weekend hack!).

But what about the traditional saw?

They are still alive and well offering saws that still offer 100% of the performance of the old saws, giving an element of truth to the old saying “You can’t make a silk purse from a sow’s ear”.

Yes, these economical saws are good to use and easy to maintain, but there is something about using a hand made saw that is difficult to describe, but easy to feel. To simply say “Hand made saws cut better” would be too much, and yet not enough of an explanation. These high priced pieces of woodworking artistry are not for everyone, but if you have the opportunity to try one, it is something you will appreciate.

(Unless it needs sharpening, then they are just a blunt tool. Which is no fun.)

I hope that makes for some interesting reading for some of you out there, it has taken a very long time for me to type it all out.

This essay is what I perceive to be the evolution of how the replaceable blade saw came about in Japan. An unusual tool for an unusual situation, and the amount of tradition crushed and abandoned to bring them to the point that they are now is simply mind boggling. Today, such a thing would be unlikely to happen in the same way. The truth may (and probably is) something different to what I have described above.

But having lived here in Japan for quite some time, I have picked up a feel for how things have changed over the years, and while it might not be something worthy of publication, it does give an idea of what happened over the years with regard to Japanese saws.

I hope you enjoyed reading this, and the next time you pick up a Japanese saw, that you think of how it came to be in your hand.

Next, a practical article on how to safely change saw blades.

Thanks for reading,


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