What’s The Difference Between a Japanese Wood Plane and a Western Wood Plane?

If you’re looking into purchasing a wood plane, then you’ve probably come across Japanese wood planes and wondered how they compare to western planes. A wood plane is a tool made up of a sharpened metal blade or plate attaches to a wooden or metal body. “Planing” is moving a plane across a wooden surface to create uniform shavings in order to correct high points and achieve a smoother surface. The hand plane is one of the most ancient woodworking tools with records of them going back thousands of years. The earliest physical plane found was discovered in Pompeii, and dates back to the first century CE.

It’s important to do some research before choosing a hand tool. When it comes to Japanese and western wood planes there are several key differences to consider. The most obvious difference is in the operation of the Japanese wood plane, called kanna 鉋. Kanna require a pull-stroke as opposed to the push-stroke used with a western plane. The two models employ different muscles, but can both be used from a standing position. One may find one motion or the other less strenuous. The other differences are more anatomical, and are best illustrated through a walk through of each plane.

The Japanese Wood Plane or Kanna

The Construction: Materials, Quality, and Features

Kanna as they appear today were introduced in Japan around the mid-Muromachi era (1336-1573), replacing the previous spear-shaped design. The chip breaker was added during the Meiji era (late 19th century/early20th century), and the kanna has remained pretty much unchanged since then. Modern kanna are essentially comprised of four parts: the body of the plane or kanna-dai, the blade or kanna-ba, the chip breaker or oase-gane, and the chip breaker holding pin or osae-bou. Kanna have a simple, elegant design that prioritizes function and adjustability. Kanna traditionally have no handles, a common point of concern for those used to the western model that is fitted with handles. However, if the blade has been set with care and the kanna is properly adjusted, it should plane with ease and accuracy. Kanna, like many hand tools, require careful adjustment and attention by the user to perform well.

Different types of kanna mainly differ in the width and length of the body and blade, though some kanna such as the kushi-gata-shakuri-ganna do not have a chipbreaker. In some kanna the blade is separate and must be prepared and set. However, kanna are uniform in their simple wooden body, thick blade, and ability to create a distinctively fine shave.

The Body

A good quality kanna will have a dai (body) that is made of white oak or shira-kashi 白樫. Shira-kashi is an impressively resilient, durable, and hard wood. It has been used in Japan since ancient times to make hand tools and even practice weapons for sword masters. The bottom of a kanna is not as flat as that of a western plane in order to minimize the effort needed to pull towards you, contact with the wood surface, and to allow for quick adjustments. The chip breaker has bent “ears” called mimi that control the pressure and placement of the chip breaker between the pin and blade. The protrusion length of the mimi can be adjusted by hammering or filing.

The Blade

The kanna-ba (blade) is particularly thick and heavy compared to that of a western plane. This is to lessen chattering, which is when resistance exerted by the wood forces the blade too deep causing it to skip and create digs. The blade is composed of a thin layer of hard steel forge welded to a large layer of soft iron. The iron is softer to allow for easy sharpening. The type of iron used affects the price of the plane, with the models at a more expensive price point using wrought iron, and cheaper models using low carbon iron, which is mass produced and easily worked.

The underside of the blade or ura is hollowed for easy sharpening and to allow shavings to pass by, which results in a less strenuous plane overall. The ura is a distinct feature of Japanese woodworking tools that is also present in Japanese chisels, and the most traditional and common ura shape is the bowl shape. The bowl shape itself is very subtle, and this ura requires careful maintenance as the shape tends to change with use.

Located at the top of the ura is the mei (inscription). The mei will usually include the name of the plane as well as either the maker’s name or a brand name. Though it may appear straight at first, there is actually a slight curve across the width of the kanna-ba (blade), at the ura (hollow on the back), and of course in the blade bed as well. The kanna-ba is advanced by tapping it gently with a mallet, and retracted by tapping the dai centrally.

Setting The Blade

It was mentioned earlier that some kanna require you to set the blade. On either side of the bed are tapered grooves for fitting the blade called, shikomi-mizo. The grooves must be matched to the blade and narrow as they go deeper into the body. A proper fit is snug, leaving only the slightest clearance on either side of the blade. Too snug of a fit will make adjustments difficult, so be patient when inserting the blade. This is an elegant feature of the kanna design. By holding the blade in place using the tapered grooves there is no need for an additional wedge to secure the blade like in many western planes.

Once the blade is set and the chip breaker is fitted against the holding pin, check the sole (the underside of the body). This is to ensure that where it makes contact with the wood is flat. Check the sole of the kanna without removing the chip breaker and holding pin, and ensure that they are secure and lying flat. Checking the sole of a Japanese plane is much the same as checking the sole of a western plane. A metal ruler is placed longwise, horizontally, and diagonally to check for gaps. Use sandpaper to flatten the sole. It is important to maintain the blade and ensure that it remains properly set within the body.

The Kanna Overall

The Kanna conceals a great deal of complexity within its elegant, no-frills design, its components fitting together neatly and without superfluous pieces. When used correctly, a good quality Kanna can be adjusted to have minimal contact with the wood, and achieve impressive, paper-thin shavings. Kanna are built simply for the task of planing and execute it with minimal strain.

If you are looking to get started with Japanese planes the one pictured above is a great place to start. This 58mm Kanna is fairly high quality while not breaking the bank. Its what allowed me to begin trying out Japanese planes and was the impetus for writing this article.

The Western Wood Plane

The Construction: Materials, Quality, and Features

The standard western wood plane is used with a push-stroke. The kanna’s pull-stroke, and has a few more pieces than the kanna does. Understanding them will give one a better idea of the more anatomical differences between the two. As with the kanna, we will begin looking into the western wood plane by outlining its main components. You will notice some things may be repeated here, but it’s also important for one to know the similarities between these tools.

The Body/Block

The central part of the plane is the body or block. The underside of this is the sole, where the block makes contact with the surface of the wood. In wooden hand planes, the block is made of hardwoods such as beech, mahogany or lignum vitae. Lignum vitae is the densest traded wood and actually sinks in water. The metal wood plane has a body made of ductile cast iron. This is the model we are discussing as it is the most common. The choice of a metal body is another central difference between the kanna and the western model: Japanese models always have a wooden body. The toe and heel are the front and back sections of the block, respectively. Adjust the blade at the heel by tapping it with hammers or mallets.

At this point you’ve noticed that the western style wood plane has more bits and pieces than the kanna. A possible advantage to this being that there are clear ways to make adjustments. As illustrated earlier there are ways of making these same adjustments to the kanna, but they require a bit more tact and precision. These extra components on the western model may create a busier appearance, but make for a more ready-to-use design.

The Frog Assembly

The frog assembly(# 6 in the above image) is made up of the frog, the blade, the chip breaker, the lever cap, the depth adjustment wheel, and the lateral adjustment lever. The blade is made of hardened carbon steel and rests on the frog in the “mouth.” The frog (or “bed”) is the metal piece that supports the blade assembly. It also helps prevent chattering. In some models the frog is cast as the same piece as the body. The chip breaker is screwed to the blade for support and to clip the shavings during planing. This also helps to avoid chattering.

The lever cap holds the chip breaker and the blade in position. It’s screwed into the frog through the chip breaker and blade. The lateral adjustment lever is a simple metal projection that alters the angle of the cutting edge across the sole. The depth of the blade projection affects how much of the wood is shaved. To adjust the blade depth turn the depth adjustment wheel. Clockwise will increase the depth and counter-clockwise will reduce it.

This may be more intuitive compared to the “tapping” of the body required to adjust the blade in a kanna. Bench planes generally have a handle, sometimes called a “tote,” which come in two forms: open and closed. The knob is the rounded front handle. Handles are distinct features to the western style. Kanna do not have handles, although it’s possible to fit one for them.

The Western Wood Plane Overall

The western wood plane is versatile and intuitive. It has a sturdy, reliable composition that allows one to plane uniformly and effectively. There is also the added comfort of two handles, a metal body, and readily visible and accessible ways to make adjustments.

The Differences

Woodworkers have a lot of opinions on their hand tools. When it comes to the Japanese model versus the western one, there’s no right or wrong answer. So, to thoughtfully answer the question, “what’s the difference? Which one do I want to use?” make sure to understand the anatomy and composition of each before simply looking at some bullet points and making a decision. Now that you’re an expert, here is a refresher outlining the main differences covered in the article:

 WesternJapanese
1Push-StrokePull-Stroke
2Metal BodyWooden Body
3Flat SoleCurved Sole
4~9 Main Parts~4 Main Parts
5Essentially ready to use when purchasedSome set-up required such as flattening the sole and fitting the blade
6Totes (Handles)No Totes
7Frog (additional metal piece that supports the blade)No Frog
8Always a chip breakerSome models have no chip breaker
9Lever Cap (additional metal piece that secures the chip breaker and the blade)No Lever Cap
10Depth Adjustment Wheel (used to retract and project the blade)No Depth Adjustment Wheel (Tap in different places with a mallet to adjust blade)
11Lateral Adjustment Lever (used to move the blade laterally)No Lateral Adjustment Lever (lateral adjustments achieved by tapping the dai centrally with a mallet)
  • Western Blade:
    • Thinner
    • Hardened carbon steel or “tool steel”
    • Fit by screws into the body through the lever cap, chip breaker, and frog
  • Japanese Blade:
    • Thick and heavy
    • Thin layer of hard steel forge welded to a larger layer of soft iron
    • Hollowed underside (ura)
    • Fit using only tapered grooves, acts as its own wedge

Comments

  1. Not all western planes are metal bodied, and wooden bodied western planes are adjusted the same as Japanese planes, and all good quality planes if sharpened correctly can produce a wafer thin shaving. Japanese people are generally of smaller stature and their tools have developed over a long period of time to make best use of their smaller size. Amazing craftsmen of both cultures produce produce quality workmanship and neither is superior in my opinion.

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