Putting chisels to the test

Early on in ones journey as a woodworker in the West, one hears the siren song of Japanese chisels. The only reason that one should own western chisels is if you like to sharpen tools. That’s a bit of an exaggeration but has a bit of truth to it. One of the challenges with purchasing Japanese chisels is that the culture surrounding how they are made is slightly different than in the West. In the West, contemporary chisels are made by industrial processes and marketed to Western woodworkers. Stanley, Buck Brothers, Two cherries, Marples, Narex, and Lie-Nielsen are some of the brands that you may find in the sales materials of a woodworking store. In contrast, Japanese tools were primarily developed for the domestic market in Japan because of geographic, cultural, and language differences. Producers of hand-tools, like chisels, in Japan are done on a much smaller scale and steps in the production process rely more on handwork by the blacksmith. The quality of the chisel then depends more on the skill of the blacksmith. While the skill of the blacksmith may result in a better performing product, the variability among chisel “brands” may be higher. 

Industrial processes improve consistency associated with a product by decoupling the quality of the product from the skill of the “maker”. In both the west and Japan, pre-industrial woodworking blades, which include both hand planes and chisels, used forged blades, where a brittle high carbon steel cutting edge was laminated to a resilient low carbon backing steel. The grafting of a thin high carbon edge steel onto a low carbon backing steel enables the tool to be honed to an extremely sharp edge while being resistant to chipping and easy to sharpen. The manual labor required during the forging process doesn’t translate well to industrial processes. As a result, plane blades and chisels made by industrial processes are made entirely from the same steel that has averaged material properties compared to the forged blade. 

In the past, there were 100’s of blacksmiths in Japan making tools under their own trademark brand or for someone else’s brand. Only a handful of these makers sold their wares to the West. Selling in the domestic market was very competitive with one’s reputation as a maker of a high quality product was held to the highest standard. As the domestic market shrank, even high quality makers had a difficult time making a living. Selling to the west was one option where barriers in the distance and language between maker and consumer could reduce the importance of maintaining your reputation as a maker and increase importance of marketing your product. Which leads to the goal of this post, given the variety of Japanese chisels on the market, how do you know that particular chisels are good? To answer this question, I decided to run an experiment where I would similarly sharpen a collection of different 1/2” chisels and compare the results after similar use.

The contenders

1. Irwin Marples 1/2” chisel purchased from a big-box store. As a representative “Western” chisel, this serves as the control in the experiment. 

2. Matsumura brand 12mm “blue steel” bench chisel (mentori oire nomi) with red oak handle purchased from Japan Woodworker in the early 2000’s. Maker is no longer producing chisels.

3. Unclear brand 12mm chisel (kakuuchi oire nomi) with red oak handle purchased from Japan as part of an assorted chisel lot in an on-line auction. 

4. Fujihiro brand 15mm “white steel” bench chisel (mentori oire nomi) with red oak handle purchased from a tool reseller based in the US. These chisels were hand forged by Chutaro Imai, a blacksmith who has been making chisels almost 50 years and is located in Sanjo City, Niigata prefecture.

5. Oguro brand 12mm bench chisel (kakuuchi oire nomi) with red oak handle purchased from Japan as part of a 10-piece “new old stock” set in an on-line auction site. 

6. Yoshimasa brand 12mm bench chisel (mentori oire nomi) with red oak handle. These were made at the Motomiya Chisel Factory (有限会社本宮鑿製作所) in the Echigo Sanjo region by the traditional craftsman Takamasa Toriyama (or Katsumasa Karasuyama) that produced chisels (20+ years ago) under this trademark. The Motomiya Chisel Factory does not appear to be still in business. These “new old stock” chisels were purchased from Japan in an on-line auction.

7. Mitsuhiro brand 12mm bench chisel (mentori oire nomi) with white oak handle purchased from a tool reseller based in the US. 

8. Ichisada brand 12mm dovetail bench chisel (shinogi nomi) with different wood handle purchased at part of a used 8-piece set from Japan in an on-line auction.

9. Kikuhiromaru brand 12 bench chisel (mentor oire nomi) with red oak handle. This chisel was hand forged by Kazuyoshi Nagaoke, a blacksmith in Sanjo City, Niigata prefecture. These new old stock chisels were purchased from Japan as part of an assorted chisel lot in an on-line auction.

10. Covington brand 12mm bench chisel (mentori oire nomi) with white oak handle purchased from Stan Covington & Sons, an on-line reseller based in Japan that subcontracts blacksmiths to make tools for them.

11. Kunikei brand 12mm bench chisel (mentori oire nomi) with red oak handle that were originally sold by Japan Woodworker in the US in the early 2000’s. The maker of this brand recently passed away.

Protocol

1. Flattened the back of each chisel on a mild steel lapping plate, called a kanaban, with lapping grit from a 1000 grit Norton water stone. 

2. Sharpened the bevel at 30 deg using an Eclipse-style honing guide with a progression of 1000, 4000, and 8000 grit Norton water stones.

3. Chopped 10 x 2mm slices vertically through 1” thick kiln-dried white oak board using a 430 gram hammer as a driver. The edges of each slice were precut with a tenon saw to be the width of the chisel.

4. Chopped one 2mm slice vertically through a 1” thick white pine board using a 430 gram hammer as a driver. The edges of each slice where precut with a tenon saw to be the width of the chisel.

Results

Appearance

Overall the finish of the chisels varied a bit. The Marples chisel seems most futuristic with it’s colorful and transparent handle, which contrasted starkly with all of the Japanese chisels. Focusing in on the Japanese chisels, there were some more subtle differences. In particular, there is shaping of the transition from the blade to the neck of the chisel and how well shaped is the backside of the chisel blade. One of the defining features of a japanese chisel is the hollowing out of the backside of the chisel, called Ura, to ease sharpening. Instead of trying to flatten a large surface of hard steel, the hollow reduces the contact area to more quickly flatten the leading edge of the chisel. All of the Japanese chisels except one had a single hollow while the Ichisada dovetail chisel had two hollows. The symmetry and size of the Ura is an easy visual cue as to the attention to detail of the maker. When purchased, the Ura might look symmetric but the Ura may become distorted during flattening process. Chisel 3 is an example of a distorted ura (left in figure below) that is in contrast to some of the more well done ura (Oguro, Yoshimasa, and Mitsuhiro).

In the case of blacksmith-made chisels, the transition from the blade to the neck of the chisel is done using a file and is also an easy visual cue to the attention to detail of the maker. Chisels made in the Japanese style by factories tend to have a rough drop-forged finish to the upper surface of the chisel. Chisels with this rough finish are not likely high quality and were not included in this comparison. For blacksmith-forged chisels,  Chisel #3 is an example of a rough transition. In addition, the interface between the chisel blade and the ferrel on the handle also had some gaps. While having a well-formed ura, the neck transition was a bit rough on the Fujihiro chisel. In contrast, the neck transition on the Mitsuhiro and Ichisada chisels were well done. 

Human interaction with the chisel happens through the handle. Large handles like the Marples make the chisel unbalanced and almost unwieldy in use due to its top-heavy nature. Handles on the Japanese chisels were smaller and made the chisels well-balanced and easier to use. Differences in the handles of the Japanese chisels were more subtle. In some cases, the handles were made by a different craftsman and labeled with their trademark, which in this case was Kanei. Mastumura, Mitsuhiro, Kunikei, and Kikuhiromura brands all had Kanei branded handles. Apparently, branded handles can also vary in quality. The Mitsuhiro chisels have the ideal handle, which is from a branch with the pith in the center. Alternatively, the grain should be straight. Grain runout can lead to failure of the handle, which happened with a 18mm Matsumura chisel.

Ease of sharpening

There was a bit of variation in the sharpening among the chisels. A sharp edge is created by a zero-radius intersection of two planar surfaces, which are the back and the bevel. Sharpening a chisel is the process to create the two planar surfaces. Typically one starts with flattening the back. Time spent on flattening the back depended on how flat the chisel came from the maker. A slight concavity to the chisel is tolerated as that means that the leading edge is flattened first. In use, the back provides a reference surface for cutting. Too much concavity leads to problems in use of a chisel as the chisel tends to dive into the work instead of cutting straight. Convexity of the back is problematic in a chisel as it will take a long time to flatten the back. The back of the Marples chisel was the worst with significant convexity and twist. Luckily the leading edge was flattened first so it didn’t take much time to flatten but this chisel would have a tendency to dive in use. Chisel #3 was the most difficult to flatten and the ura was most distorted in the process. Due to the well-shaped ura, the Oguro, Yoshimasa, and Mitsuhiro chisels were easiest to flatten.

An Eclipse-style sharpening jig was used to flatten the bevel at a consistent angle among all of the chisels. I chose a 30 degree bevel, which is typical for bench chisels. From the manufacturers, the bevel angles were a bit different among the collection. The Marples chisel had a 25 degree bevel to start while many of the Japanese chisels were somewhere around 30 degrees. The Kunikei chisel had a bevel of around 33 degrees. Kunikei chisels are known for their edge retention and I wonder if the steeper angle contributes to that performance. So instead of trying to lower the bevel angle on the Kunikei chisel to 30 degrees, I decided to exclude this chisel from further testing.

Ideally, a thin layer of hard steel is laminated in a U-shape to the softer backing steel, as illustrated by the Yoshimasa chisel. Some of the more recently factory produced chisels in the Japanese style have a flat lamination line and not a U-shape lamination. This is one indication of a lesser quality factory-made chisel. Less attention to detail of the blacksmith during the forging process leads to an uneven lamination, as illustrated by chisel #3. Generally, a thinner hard steel layer can be sharpened more quickly than a thicker hard steel layer. As expected, chisel #3 with a thick lamination took the longest to sharpen the bevel due to a combination of having an initial bevel angle steeper than 30 degrees and a thicker hard steel layer. The bevels on the Oguro, Yoshimasa, and Mitsuhiro chisels were easiest to hone.

Putting them to the test

Overall, chopping of the 2mm thick slices of oak was relatively straightforward. Chopping required holding the chisel in the left hand with the left elbow resting on the board to give an additional point of contact to stabilize the chisel. The right hand wielded the hammer to deliver vertical taps to the chisel handle. As mentioned previously, the large handle on the Marples chisel made this chisel difficult to use as it seemed top-heavy and tippy. All of the Japanese chisels performed similarly in this regard as they were similarly balanced. Once 10 2mm slices were taken from the end of the white oak board, we can see that there is little difference among the tested chisels in terms of the quality of the cut. I did notice however that the Marples chisel seems to take the longest towards the end as each blow of the hammer didn’t advance the chisel very far. Differences among the Japanese chisels in chopping the oak didn’t seem as noticeable.

Chopping the end grain of white pine after the oak revealed key differences in the quality of the edge among the chisels. White pine is a much softer wood than oak and a sharp edge is required to cut the fibers. If the edge is not sharp, the wood becomes crushed before it cuts. We can see that the Marples chisel was the worst performing chisels in chopping pine as wider gaps can be seen indicating that more of the wood fibers were crushed before they were cut. The next performing group of chisels were Chisel #3, Fujihiro, and Oguro, which all three seemed to lose sharpness from chopping oak. Looking at the cutting edge, all three seemed to have slight chips at the leading cutting edge. The Matsumura chisel seemed to perform slightly better. Yoshimasa, Ishisada, Mitsuhiro, Kikuhiromaru, and Covington brands performed really well with the latter three seeming very slightly better.

Limitations of the study

Japanese chisels are largely hand-made by a blacksmith. In contrast to products made by industrial processes, hand-crafting introduces more variability into the finished products. While that variability may be not noticeable by the end user, a small random sample, which here is a sample size of 1, may not be entirely representative of a particular brand. In addition, a particular chisel brand may subcontract out to different blacksmiths to make their product or the skill of the blacksmith can improve with experience and can diminish in old age. Collectively these factors can lead to variability in the quality of a brand over time. Given those caveats, the results presented here are more to illustrate a process for evaluating/selecting chisels rather than absolute recommendations for particular brands. There are so many other blacksmiths from contemporary and bygone times that produced excellent chisels that we haven’t tried.

Summary

The Marples chisels was the worst performing chisel. While relatively cheap, it was difficult to use and would require the most frequent sharpening. I’ll be getting rid of those shortly because I already have a chisel dedicated to scraping stuff. While more of a pleasure to use than the Marples, Chisel #3, Fujihiro and the Ogura brands are more of the entry-level Japanese chisel that, once set-up, require a bit more sharpening. The best performing brands – Yoshimasa, Ishidaa, Mitsuhiro, Kikuhiromaru, and Covington – hold an edge much longer. These are considered professional-level tools and are a pleasure to use. Awareness of these different brands in the west is a bit mixed. Ideally, quality is best assessed by use. With increased access to the Japanese market over the internet, knowing what to look for visually can increase the chance to get some hidden gems. Assuming that one can avoid factory made chisels in the Japanese style, worst case is getting a blacksmith-made chisel that is still better than what you can get at your local big-box store. Happy chiseling.