It is well documented that Japanese tools are used largely on the pull stroke, rather than the western-favoured push stroke. Kanna (鉋),wooden bodied, hammer-adjusted Planes, are pulled towards the user to make a cut, and nokogiri (鋸), Japanese saws, have teeth angled towards the user so that they cut the timber fibres on the pull stroke.
In the case of saws, the pull stroke has profound effects on the anatomy of the tool. Western saws must resist the buckling forces of cutting on the push stroke through thicker and more malleable blades and a heavy spline added to the top edge. The act of pulling a Japanese saw through the cut, however, results in the blade naturally tensioning itself. The benefits are eloquently described by Toshio Odate in his book, Japanese Woodworking Tools:
‘The pull stroke prevents the blade from bowing, so a thin, brittle steel can be used; because the steel is so thin, the blade cuts a narrow kurf, and the saw cuts down the wood fast. The thin blades also enhances accuracy – just as people often react to the sensitivity of a fine pen point by writing smaller, more delicate letters, a fine blade encourages delicate, precise cuts.’
The speed of Japanese saws, combined with the precision of the cut, promotes wider use of hand-sawing. The flexibility of cutting joints by hand, as opposed to the sometimes-laborious job of setting up machines, is infused through Japanese making, and often leads to unexpected, quirky details.
Japanese planes are very special pieces of technology, and various aspects will be discussed in more detail in later blog posts. However, the act of pulling the plane towards the body is fundamental to it’s success as a tool.
Japanese woodworkers traditionally work on the floor, and pulling tools were preferred as they allowed the maker to generate more power from a seated position. However, it also fosters a more controlled, careful engagement with the timber. The act of pushing a tool through a material requires an explosive burst of force. As the plane moves away from he body, the control the user has over it diminishes. It also becomes harder to physically see what the plane shaving is looking like – an invaluable measure of the quality of cut being achieved. As Japanese planes are drawn towards the body, the cut is under ever-increasing control, and the shaving is constantly visible.
The wooden body of the plane also provides tacit knowledge to the user. Chatter, timber density, and difficult grain can all be felt more accurately through the body of the plane.
Although Japanese saws and planes are well known, it was a surprise to see the same pull-stroke employed in the use of knifes. A technique used extensively in the preparation of bamboo for basket making requires the knife to be held firm against the user’s knee while the bamboo is pulled past the blade. A block of wood is used to support the bamboo, and helps to maintain a constant thickness to the remaining material.
This most traditional of techniques has influenced a whole suite of processes that are combined in preparing bamboo lathes for weaving. Having tried these techniques first hand, I can say that there is something very different about pulling the material through a blade, rather than pushing a tool over it. For a start, it allows for thinner, more delicate material to be processed. Secondly, it focuses the users attention on the exposed blade edge where all the action is, rather than on the inert body of the tool. Lastly, by holding onto the material, the maker can feel the stresses and strains that it is being subjected to, and alter their technique accordingly.
The pull stroke is one of the key differences between Western and Japanese woodworking. It is all-encompassing in it’s ramifications – in the anatomy of the tools, in how the tools are used and experienced, in what kind and size of wood is processed, and in what information is fed back to the maker during use.
Having now experienced the Japanese ‘pull’ techniques, I have been convinced that the pull-stroke allows for more control, offers increased accuracy, requires less effort, and provides more nuanced feedback. I’m a convert.