Tool Review - The Dozuki

Two Japan made Dozukis - a Z-saw and a Razorsaw

Ever since Kuldeep Singh from Kyoto sent me a Japanese saw a couple of months ago, I have been tempted to find out more about them and their capabilities. This was not easy at first because there are so many types of Japanese saws and different manufacturers. I did not know where to start. 

My immediate need was for a fine toothed saw that could cut tenons, dovetails and box joints. A little reading on the Internet suggested that the Japanese saw known as the Dozuki would be the most appropriate. So I ordered two of them - one from Amazon.com in the United States and one from toolsfromjapan.com in Japany. Both the saws arrived in about two weeks. 

The one purchased from Japan is a fine toothed 240mm long saw made by the Okada Hardware Manufacturing Company (website: http://www.z-saw.co.jp) which is known for its Z-saw range. This saw too was a Z saw, a standard Dozuki type which as the online retailer explained, is a backed saw that utilises “a 'hook' blade retention design along with a steel spine to keep the thin, delicate blade straight during cutting. The cross cut teeth will allow ripping, albeit at a slower rate than a more correct rip tooth might, but this may offer greater control in cut depth.” 

I had chosen a wider than normal saw because I also wanted to cut tenons with it and this one had an extra 10mm depth of cut over the standard saw. Its handle is made of solid wood wrapped in rattan and the saw is beautifully balanced. This saw cost me 2695 Japanese Yen plus 400 Yen for shipping, which worked out to about Rs 1,800.

The other one was a Gyokucho Razor Dozuki Saw also a Dozuki but a smaller - 180mm - version. The blade has 17 teeth per inch and is equally well balanced. This saw too has an easy blade removal system that allows different blades to be attached to the plastic handle. This saw cost me $28.20 plus $8 import duty or about Rs 2,100. There are various types of these Dozukis and this one is a #290 called a Usuba by the manufacturer, Razorsaw Manufacturing Company. 

The Gyokucho Razor saws, I am given to understand, are the best-selling replaceable blade Japanese saws. The ads say that they “are precision ground to a tolerance of 1/100mm, the teeth are differentially hardened, one at a time, using a much more refined version of impulse hardening. Each Gyokucho saw blade is scanned and checked by image comparison software to ensure exceptional standards of quality control.”

Both the saws are typical Japanese saws that have teeth inclined towards the handle which requires a pull stroke for cutting unlike Western saws which cut on the push stroke. The blade of these Japanese saws is just about 0.3mm wide and is much thinner than Western saws which usually have much thicker blades. Thin blades remove less material and therefore require less effort to use. Both saws come with a cover that would prevent damage to the teeth and help somewhat in rust prevention.

Test Cuts

Both the saws are a delight to use and are good enough both for rip as well as crosscuts, except the Z-saw was somewhat slower in making rip cuts as the seller had said. But it hardly made a difference given that the cuts for joinery are relatively small. 

Both the saws produced extremely fine, straight lines and cut with the minimum of effort. Compared to my regular saws, these did cut through hard Teak wood like knife through butter! They were absolutely amazing and after using them I immediately realised that they were shoulders ahead of the typical Western or Indian saws. The precision and finish of the cuts were truly amazing. A pieces of plywood crosscut with both saws produced an edge as fine as any that could be produced by a chop saw.

Plywood Crosscut with Dozuki produced a polished surface

I next used both to cut a test tenon. First I marked out the tenons with a mortise gauge and marked the shoulder with a knife line. Then I used each saw to cut one cheek. The cuts were perfect, if not outstanding. After this, I am going to stick to the Dozuki for cutting joints.

Knife line marking Tenon shoulder

Knife line enhanced with chisel

The Tenon cut with the Dozuki

 

Japanese Tradition

The Dozuki speaks volumes about the centuries old Japanese association with woodworking. The Dozuki’s lineage suggests a great tradition of woodworking as well as hand tool manufacturing in that country. 

Unlike in India where most woodworking tools are copies of Western ones, Japanese tools are unique and are the outcome of centuries of indigenous development. Western woodworkers are only now beginning to discover Japanese hand tools and their incredible precision.

The hand saw in Japan is known as the Nokogiri and its earliest forms appeared in the late Kofun era around 500 AD. The oldest surviving specimen of a Nokogiri was found in Japan’s Horyuji temple, the pagoda of which is considered the oldest wooden building in the world. This temple is believed to have been built in 711 AD after an older temple in the same spot was destroyed by lightning a few decades earlier. Much improvement was made to the Nokogiri in the Meiji period (1868-1912). 

The term Dozuki comes from Dotsuki-noko meaning a single edged crosscut saw. The blade is thin and reinforced at the non-cutting edge with a metal spine very like the one in Western backsaws. It has fine teeth for precise cuts and is suited for work that requires accuracy such as dovetail joints.

Even within the Dozuki range many variations have been developed for specific tasks and materials. For instance, today the Japanese Razor Saw Company produces Dozuki variants called Usuba (which has fine teeth along its curved tip for starting round holes) and Jyushi (for cutting acrylics apart from wood), apart from other variants.

 

Ryoba

Apart from the Dozuki, the Japanese have developed many other kinds of saws for specialized purposes, including the general purpose saw Ryoba, which has cutting edges on both the top and bottom of the blade, one of which is used for rip cuts and the other for crosscuts. Over the next few months, I hope to explore different types of saws and other Japanese hand tools.

Indranil Banerjie
25 July 2013