The Japanese Gennou (Hammer)

[Stanley Covington]

There have been several posts lately that have involved hammers in general and Japanese gennou in particular, so I thought it might be helpful to those who do not have much experience with gennou, or that find using a hammer tiring or painful, to post some pics of a couple of my hammers and make some suggestions you might find useful.

First, some definitions. The generic term for hammers in Japanese is kanazuchi 金槌。A gennou 玄翁, on the other hand, is specific type of 2-faced (not a politician) hammer used primarily for woodworking with a flat face on one side and a slightly rounded face on the other. The flat face is intended for striking chisels, planes, and driving nails. The round face is for kigoroshi (bruising wood fibers) and setting nails (last stroke after driving). There are different varieties of gennou, but the ones shown here are the most common type in the Tokyo area. Both heads are shaped slightly differently, with the lighter one being older and of an antique design, but I like it.

Both heads were made by Kosaburo 幸三郎　(長谷川幸三郎), a Tokyo blacksmith who passed away 20 years or so ago. He is said to be the best gennou blackmsith ever.

I made the handles out of black persimmon, a very dense fruitwood highly prized in Japan.

I designed the handles to fit my hand and arm, with the length based on a portion of the length of my forearm. All my gennou handles are the same length from centerline of hammer face to handle's butt (with some minor variations to compensate for handle thickness). As in golf, the swing is the swing, so I do not choke up on my handles. Because of this, I always know exactly where my hammer head will strike without thinking, adjusting my grip, or even having to glance at the hammer. It is an extension of my fingers.

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Notice that the handles are curved, rotating the flat face used for striking chisels down towards the handle's butt. The first photo shows the gennou oriented as if striking a chisel with the flat face facing downwards. The second photo shows the same gennou with the flat face on the right. This is intentional. The amount of this curve depends on the length of the head, so that the curve on the bigger gennou's handle is greater than that of the smaller gennou. This design orients the centerline of the hammer head in very close alignment with the centerline of the chisel handle at the instant of impact, ensuring maximum transfer of energy, minimizing induced vibration in both chisel handle and hammer handle, improving control, and aiding a quick return to battery. Of course, the head's face will be perpendicular to the chisel handle's end at the same instant.

The angled head is the purpose of this design detail, not the curve, which simply facilitates a smooth transition. Some men choose to make the change in angle abrupt, and to my eye, clunky, but that is personal preference. The degree the head must be angled to achieve the ideal alignment between head and chisel handle in use varies from individual to individual. It took years and multiple iterations to develop these dimensions and angles to match my body, the way I work, and my various gennou heads.

When making a gennou handle, be sure to avoid excessive grain runout in the skinny neck area. The greater the curve, the more critical this becomes.

The heads are not secured to the handles with wedge or pins, but are a friction fit in the rectangular eye, which is not tapered in any direction. Some people like to have the wood projecting out of the eye on top. I was taught to either cut it off flush, or better yet, leave the handle slightly recessed inside the eye. As the handle gradually loosens during years of stress, it can easily be driven further into the eye to tighten it up, and will eventually project from the eye. But a recessed handle makes for a neater, more professional appearance IMO, especially when the handle is new. But this is just personal preference.

The first hammer head weights 560 grams (app 20oz). This one is suited for driving heavy chisels such as tataki nomi for structural carpentry and timber framing work. It is too heavy for the more common but lighter-duty oire chisels. I bought it in 1986 (I think).

The second hammer head weighs 375gm (app 13oz). This is a tad on the light side of standard carpenter's gennou, but a tad heavier than what I normally use for joinery and carcase work. I made this handle using the same design parameters as my other gennou, but with different dimensions because of its shorter head and much narrower and shorter eye. The distance from the head's face's centerline to the end of the hammer is approximately the same as the previous heavier gennou because the "swing is the swing."

Allow me to point out several other key points. First, in each case, notice that the handle's sides exiting the eye are straight, with no shoulders. This detail eliminates useless wood, improves balance, reduces air resistance, and greatly reduces vibration reaching the hand. To armchair critics: Give it try before you cry BS or risk being trollish.

Second, notice how the front and side surfaces flair out towards the butt end This detail makes it very easy to hold the hammer securely with only a light fencer's grip while maintaining a flexible wrist, resulting in greater precision and speed with less effort.

Third, notice how the back surface at the grip area is nearly flat, not rounded. I like a wide, flat area here to spread the reaction impact across the heel of my hand where the bone is located just above wrist and below my pinkie finger. A rounded shape here will cause the handle to bruise the bone making my hand sore. This detail is key to using the hammer hard all day without tiring.

Fourth, the front surface near the butt is rounded to make it easy to wrap my fingers around without causing blisters.

Fifth, notice how the two sides of the handle where my thumb and index finger pinch the handle are flat with tightly radiused edges, and are parallel to each other. This detail not only improves my grip, but makes it possible to sense the orientation of the hammer's head at all times and without having to look at the hammer.

Although it is not apparent from the photos, I am not gripping the handle in my fist, but diagonally across the palm touching most strongly at two locations. The first location is the bone located at my palm's heel, just above my wrist and in line with my pinkie. The second location is the space between the first and second joints of my my index finger. This grip was taught to me by my father, who was a carpenter, when I was a boy. It is very common among men around the globe who use hammers constantly. I call this the "Ben Hogan" grip because it resembles the golf club grip that excellent athlete taught.

Fitting the handle to the head in this way makes using the tool instinctive, more efficient, and less tiring. I can pick up the handle and tell the front face of the head from the back, and immediately know the precise angle of the face simply by touch and without looking at the gennou. By comparison, standard one-size-fits-all oval cross-section handles are tiring, inefficient, and clumsy in my experience.

I did not think up these design details. They were developed by specialist carpenters over a period of several hundred years. I adapted them to my body, my gennou heads, and the way I work.

I hope this will clear up some confusion, and gives you a small amount of food for thought in making your own tools more efficient and ergonomic.

Stan

[Pat Barry]

Wow! Lots of great info Stanley. Thanks for taking the time to illustrate and discuss the rationale for the key ideas.

[Phil Mueller]

Thank you Stanley! I was quite unfamiliar with the Gennou or its design characteristics. Beautiful execution!

[Stanley Covington]

Pat and Phil:

You are quite welcome. I hope it proves to be useful information for you both.

Stan

[Brian Holcombe]

Thanks Stanley! Great post! Those handles are works of art in and of themselves.

Even the work of Kosaburo's students is very hard to find, I managed to find a dealer who had a few Hiroki's and still regret not buying all of them.

[Stanley Covington]

Thanks Stanley! Great post! Those handles are works of art in and of themselves.

Even the work of Kosaburo's students is very hard to find, I managed to find a dealer who had a few Hiroki's and still regret not buying all of them.

Glad you like them, Brian. I hope to emulate you and someday get a planing robe and embroidered planing slippers. I snagged some carpet tile samples from a mockup for my current jobsite that were going to be tossed, so I hope to have carpet on my workshop floor like yours before too long.

Hiroki makes a great gennou head indeed. Dieter Schmidt appears to have a good selection in stock at competitive prices.

Stan

[Derek Cohen]

Thanks Stanley. This is interesting.

I've used various mass-produced gennou for years now, ranging in weights from 250 - 450gm. Five or six years ago I purchased a 375gm Tenryuu head (Tsuchime finish and Daruma style) from So Yamashoto in Sydney.

So gave me some advice on making a handle, which I shaped from Jarrah.

This gennou is my go-to for joinery with Japanese chisels.


http://www.inthewoodshop.com/ShopMadeTools/AHandleforaGennou_html_3018016f.jpg


http://www.inthewoodshop.com/ShopMadeTools/AHandleforaGennou_html_m73069e39.jpg

Article on making handle on my website: http://www.inthewoodshop.com/ShopMadeTools/AHandleforaGennou.html

Regards from Perth

Derek

[Dave Beauchesne]

Stanley -

Thanks so much for taking the time to explain the nuances of proper handle design and construction for us.

Beautiful tools and handles: may I ask what the scale ( size of the squares ) used as a backdrop for the photos??

Dave B

[Stanley Covington]

Stanley -

Thanks so much for taking the time to explain the nuances of proper handle design and construction for us.

Beautiful tools and handles: may I ask what the scale ( size of the squares ) used as a backdrop for the photos??

Dave B

You are welcome, Dave.

The board the hammers are resting on is a thick wooden gameboard (more like a small, squat table) for "Igo" with 23mm squares.

Stan

[Stanley Covington]

Thanks for the pics, Derek.

Beautiful heads and handle. Tsuchime is one of the few decorative finishes that improve with age.

Stan

[Brian Holcombe]

Glad you like them, Brian. I hope to emulate you and someday get a planing robe and embroidered planing slippers. I snagged some carpet tile samples from a mockup for my current jobsite that were going to be tossed, so I hope to have carpet on my workshop floor like yours before too long.

Hiroki makes a great gennou head indeed. Dieter Schmidt appears to have a good selection in stock at competitive prices.

Stan

Lol, and I mean literally. My wife starts to think I'm losing it when I literally laugh out loud when reading something.

I would not be surprised if the carpet somehow catches on.

Ok, I want to play also;

http://i27.photobucket.com/albums/c181/SpeedyGoomba/2D84A1ED-EEE8-45C3-AE73-DF84496DC61F_zpsmf0gmcgn.jpg

My Hiroki is in the middle of getting the handle tapped in further, so the stub has not been trimmed back.

[Stanley Covington]

Lol, and I mean literally. My wife starts to think I'm losing it when I literally laugh out loud when reading something.

I would not be surprised if the carpet somehow catches on.

Ok, I want to play also;

http://i27.photobucket.com/albums/c181/SpeedyGoomba/2D84A1ED-EEE8-45C3-AE73-DF84496DC61F_zpsmf0gmcgn.jpg

My Hiroki is in the middle of getting the handle tapped in further, so the stub has not been trimmed back.


Thanks for the pics, Brian. Beautiful tools indeed. I love the colors in the steel.

If your wife suspects that laughing while reading about woodworking and tools is a prelude to insanity, I suggest you comeback with a question about the sanity of having so many handbags, or shoes, or sweaters, or whatever clothing or accessory she has too many of.

On second thought, don't :D

Stan

[Brian Holcombe]

:D Exactly....insane maybe....but I would never do anything that crazy, hehe.

How do you feel about mokume gennou? I like them, they seem like one of the few tools where that sort of thing would be acceptable. Baba makes them, but his patterns are not for me.

[Jeff Bartley]

Great info Stan! Thank you for providing so much info! I wonder if the black persimmon you used is closely related to the persimmon found in North America? Maybe it too is black persimmon? I used some for a mallet handle and it was fantastic stuff; it's on my list of wood to buy immediately should I ever find it.
And Brian and Derek, thanks for the pics too!

[Jim Koepke]

Thanks to all for the education.

jtk

[Warren Mickley]

The Japanese persimmon, Diospyros kaki, is in the same genus as our American persimmons. We have Diospyros virginiania, (NJ and PA south and west) and D. texana (CO to TX). Common ebonies are also in this genus, Makasser, Gaboon, and others.

[Stanley Covington]

:D Exactly....insane maybe....but I would never do anything that crazy, hehe.

How do you feel about mokume gennou? I like them, they seem like one of the few tools where that sort of thing would be acceptable. Baba makes them, but his patterns are not for me.

I find the mokume finish attractive, but I have no experience with it in anything but knives. Since it is an acid etch over differing layers of metal, it seems like it might not improve with time and wear, but I don't really know.

Stan

[Tony Wilkins]

Thanks for posting this Stan. Very informative.

[Frederick Skelly]

Thanks Stan! I always enjoy your tutorials!
Fred

[Stanley Covington]

Thanks Stan! I always enjoy your tutorials!
Fred

Fred:

It is my pleasure!:)

Stan

[Mike Holbrook]

Wait, I have more questions!

Brian was kind enough to answer a couple questions via PM. It seems the more I learn the more there is to learn.

I am wondering why there are square, octagonal, round and shorter round shapes for these tools? I ordered a couple with the short wide round shape simply because "I have heard" how painful it is to smack a finger/hand with a hammer. I am hoping the wider head will reduce the chance of my having to repeat errr experience that sensation. I thought the wider head might spread the shock/damage setting nails or driving chisels?

I also wonder what weights people like. Apparently Derek's favorite is a 375g model. I think Brian has a 675g gennou for mortising, woow! Stanley hints at what sizes he likes but does not exactly own up. I started with lighter models than Brian, at least until I earn my robe and slippers. My current Japanese chisel collection has more light and medium weight chisels. I believe my heavy Swedish gouges are designed to be hit with wood mallets.

[Stanley Covington]

Wait, I have more questions!

Brian was kind enough to answer a couple questions via PM. It seems the more I learn the more there is to learn.

I am wondering why there are square, octagonal, round and shorter round shapes for these tools? I ordered a couple with the short wide round shape simply because "I have heard" how painful it is to smack a finger/hand with a hammer. I am hoping the wider head will reduce the chance of my having to repeat errr experience that sensation. I thought the wider head might spread the shock/damage setting nails or driving chisels?

I also wonder what weights people like. Apparently Derek's favorite is a 375g model. I think Brian has a 675g gennou for mortising, woow! Stanley hints at what sizes he likes but does not exactly own up. I started with lighter models than Brian, at least until I earn my robe and slippers. My current Japanese chisel collection has more light and medium weight chisels. I believe my heavy Swedish gouges are designed to be hit with wood mallets.

Mike:

Good question. Idunno why the many shapes, perhaps for the same reason there are so many shoe styles.

I can confirm what you heard about smacking fingers.

The daruma style (named after the buddhist priest of legend who meditated for so long he lost his ams and legs) has a wider face and so is preferred by carvers who need a wider face because they switch chisels every few strokes and tend to choke up on the handle instead of changing hammers so they lose the sense of the precise location of the gennou's face. But I have never heard of selecting a wider face so it hurts less....:D

I like round faces for nailing, but the square face with rounded corners for everything else. Actually, for nailing, the Yamakichi style works better than the standard symmetrical gennou IMO. I am not overly fond of the 8 sided heads, although I have several. They tend to dig into the wood's surface too much when doing kigoroshi, ruining the fibers.

I just got hold of 5 new gennou heads. From the left:

1. 100 monme (375gm, 13.23oz); Kosaburo (Hasegawa Kosaburo, RIP)
2. 100 monme (375gm, 13.23oz); Hiroki (Aida Hiroki)
3. 90 monme (337.5gm, 11.9oz) Hiroki
4. 80 monme (300gm, 10.6oz) Hiroki
5. 60 monme (225gm, 8oz) Hiroki

As for weights, the 100 monme is the standard carpenter's gennou in Japan. Most people can do most anything they need to with it.

I have a couple of these of course, but what I use varies with the job. The gennou must be matched with the chisel, the chisel with the wood and the depth and dimensions of the cut and the required speed and precision. I tend to prefer lighter chisels for most chisel work such as cutting joints for joinery, furniture and casework. A 60 monme (8oz) by Kosaburo is the weight of the hammer I use the most nowadays. Good control, nice period, good rhythm.

For rougher work, a 100 is a good weight. That is the weight of the smaller gennou in my previous post.

For structural joint cutting, a 250 monme (938gm, 33oz) is a good authoritative weight for hogging wood using a stout tataki chisel by Kiyotada or Usui with a durable edge. But a gennou this size will overwhelm a smaller oire nomi. That is the weight of the big gennou in my previous post.

I am still searching for a suitable planing robe and slippers.

2d

PS: The Kosaburo at the far left is an older style, and harder to make. Notice the swell in the middle. You don't see many like that around anymore. It is new, but old stock, and the storage conditions were not optimal as witnessed by the rust. The advantage to a simple, undecorated head IMO is that it ages well and develops character, growing in wabi sabi, instead of just looking worn out and dirty. I got it at a good price from a store that knows how much I like Kosaburo's products, and that I don't mind a spot or two of rust.

Hiroki was one of Hasegawa san's apprentices, and is said to be as good as his master in most respects. Very precise eye. Properly aligned. No twisting. Clean lines. A great gennou. I talked with Aida san last last Thursday, and he said he is backlogged 2 to 3 years out. Business is good.

[Brian Holcombe]

That's a great find Stanley! That shape is particularly difficult to find and quite beautiful. Amazing how a chunk of iron and steel can have such appeal.

[Mike Holbrook]

Stanley, thanks for the additional information and especially for the pictures. Still I think we need to come up with much better reasons for needing all the different shapes, less the wives start getting suspicious! My wife does not have the buy clothes for style habit so I may have trouble with the "same reason as there are so many shoe styles" argument.

I have a 225g Tenryu Daruma I am working on a handle for. I have some decent splits but my shaving horse is in pieces at the moment and I am stuck doing other things for a few days grr. I ordered a 300g, shaped more like the ones in Stanley's picture, to try too because somehow it sounded right for me and my work and I wanted to try the more conventional shape head. We will see if I get the 300g, as I added a request for a handle to a Japan-Tool Online Shopping order and I left the shipping at the low/slow level.

Brian is generous in answering most questions, but for some reason he remains tight lipped on the sources for proper slippers and robe subject.

[Brian Holcombe]

Awesome, did you pick up the 300g Hiroki?

Just remember, if you can't find a proper robe, you can always default to a reliable country tweed sportcoat and chukkas.

[Stanley Covington]

Awesome, did you pick up the 300g Hiroki?

Just remember, if you can't find a proper robe, you can always default to a reliable country tweed sportcoat and chukkas.

Brian:

Glad you like the Kosaburo. They had one last one in stock, but the rust was considerably worse. I suspect that someday I will regret not buying it when I could.

Yes, I bought the 300gm Hiroki too.

I will remember your sartorial advice. Will Harris Tweed work?

I picked up some dark blue steel-toed jikatabi that might do the job instead of slippers, but the planing robe.... that is going to be more difficult I fear.

Stan

[Brian Holcombe]

I would like to enlist your help in finding some jikatabi if you wouldn't mind lending your assistance in terms of comparing sizing.

Harris tweed is a good start :D

[Mike Holbrook]

Yes, I ordered the 300g Hiroki too. If Stanley and I both ordered from Japan Tool then I think his order went in first and he will get the only one they had. They list the 300g as out of stock now but it was still listed when I ordered. Maybe Stanley ordered from a different source? Does Brian know Japanese Gennou stock that well?

How about a nice McKenzie plaid tartan kilt or is that just not done? Air out ones differences and such.

[Brian Holcombe]

I think the plaid kilt will do well, seems like it would be right at home while riving lumber.

Stanley is in Japan so I believe he bought from a local hardware store. So only stocks one or a few of each item, so that makes sense that it went out of stock right after you ordered. 300g is good a majority of cabinet work. I like the big gennou for chopping mortises or using with a heavy chisel, but thats about it. The light one makes the rounds for dovetail work. Then I have a file finished funate shape Hiroki that I use whenever the mood strikes me.

[Mike Holbrook]

Thanks for the clarification Brian. I got a confirming email from So, and they have the money, so I think they had one when I placed the order. I just hope I did not toss a monkey wrench in the works by requesting a handle with the head. I thought I might learn what a proper handle looks like before I shave mine all the way down, although I do have Derek's design and pictures & descriptions from other members to work from.

Maybe after my kilt comes in I will toss a few cabers around, required if you are wearing a clan kilt, maybe rive a little lumber, as that does sound appropriate too....then maybe, just maybe I will be able to handle one of those 675g Gennous.

[Brian Holcombe]

They may need to contact a vendor. So's dad does the shipping and he is always on the ball, so as soon as it arrives from the vendor it will ship....in my experience.

Since it is a small operation typically they will only communicate when something ships and when the order is placed. They will also hold the order until everything is in stock.

I think a 675g might be required with a kilt, hehe.

[Stanley Covington]

I would like to enlist your help in finding some jikatabi if you wouldn't mind lending your assistance in terms of comparing sizing.

Harris tweed is a good start :D

Safety toe or plain? Velcro or traditional metal tab fasteners?

What is your centimeter shoe size? There are tables on the web that compare sizes between the EU, UK, US, and Japan which uses the centimeter size. As I understand it, the Japanese centimeter size is a line drawn diagonally across the loaded (standing) footprint from the tip of the big toe to the farthest edge of the heel. But if you get those size wrong in jikatabi, the result will be unpleasant.

The store nearby has them in two styles, all safety toe. The link is to an online retailer that has more styles. https://www.monotaro.com/s/?c=&q=%92n%89%BA%91%AB%91%DC&swc=0

This retailer says he will ship internationally. http://www.uni-work.co.jp/web/jikatabi.html

I have not seen them in Harris Tweed....:)

Stan

[Brian Holcombe]

Thank you Stan! I'll do some research in my size, that is good information to have, as I likely would have measured incorrectly with the first go-round.

[Matt Lau]

THIS is the post that you were talking about Stan!

For those of you guys on the thread, I've been pestering Stan about gennou incessantly for the past few weeks.
I have to thank him for both his generosity of information, and his long-suffering patience.

I've been playing around with some chisels that Stan got for me, as well as a Hiroki gennou that he recommended.
The more that I use these things, the more I feel that he's probably very right on all counts.

[Stanley Covington]

I finished making a new handle for one of my favorite gennou just last night, and thought I would add some pictures of it to this post. Notice that this post is two months after the original one, so you don't need to reread the entire thread.

The head is another antique style forged by Hasegawa Kosaburo perhaps 40 or 50 years ago. It has the swell where the eye penetrates the body. This style went out of fashion after WW2, but it is a bit more functional than the style commonly seen nowadays. It weighs 60 monme, or about 224 grams (7.9 ounces). This is the perfect weight for cutting mortises and other joints using chisels with a blade width less than 19mm (.75"). Your mileage will vary, but when you have a handle fitted to your body, the hammer head often works much more efficiently letting you cut more wood, quicker and with greater precision.

The wood is Osage Orange and was a gift from Matt Lau. Matt procured the wood originally for his guitar-making endeavors. Reading online, it is used for bows (as in archery) and musical instruments. It is a very dense, tough, and especially fibrous wood, unlike anything I have used before. But it can be worked without difficulty with regular tools. The dust is not irritating, but pleasant smelling, sort of like oranges.

The color is glaring. Apparently it mellows to nut brown over time and with exposure to sunlight, or so the bowyers say. I will need to leave it in the sun for a few weeks and see.

I have no doubt this wood will be tough enough, and because the head is rather light, vibration should not be a problem. It is certainly more interesting in appearance than hickory or even ash.

Stan

[Brian Holcombe]

Beautiful!

The wood appears to have a nice shimmer to it.

My experience matches yours with regard to mortising and gennou weights. After you showed me how to make a handle I realized how much more force was being applied directly to the chisel and I no longer needed to use a 650g gennou for mortising, I use the 450g now.

If anyone is reading this and wondering what difference a handle can make, you will be shocked at how much of a difference it makes.

[Phil Mueller]

Very nice, Stan! Given this whole thread, and now that I have a spokeshave somewhat figured out, I may just take a run at a handle for a couple of old heads I have laying around.
Appreciate the posting.
Phil

[Frank Drew]

The wood is Osage Orange and was a gift from Matt Lau. Reading online, it is used for bows (as in archery).

Another name for the tree, and wood, is bois d'arc, from the French for bow wood (wood of bow). I've never seen it cultivated but you'll see a tree here and there around where I live, often along hedge rows. I turned some pieces, and it works easily on the lathe, but I'll confess that I've mostly used it for firewood (it's very good for that).

[Pat Barry]

Looks sweet Stan. Could you show us a picture of how the head is secured and also, if you tell us the length you chose for this one? Thanks

[Stanley Covington]

Looks sweet Stan. Could you show us a picture of how the head is secured and also, if you tell us the length you chose for this one? Thanks

Pat:

I will take some pics and post them tonight.

Stan

[Stanley Covington]

Pat:

I wrote a long explanation, but it evaporated, so I am just posting some pics and a drawing. If you have questions, I can try to respond.

Stan
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[Pat Barry]

Pat:

I wrote a long explanation, but it evaporated, so I am just posting some pics and a drawing. If you have questions, I can try to respond.

Stan
337622337623337624337625337626
Thanks Stan. I don't see any signs of wedges with your new handle so for the head attach its just a very precise fit and then snugged up by compression (tapping it home)? Is the hole roughened up a bit inside to help with retention of the head during use or is just common to make periodic adjustments to keep it in place?

[Mike Holbrook]

Thanks for the diagram Stan. I hope to finally finish my shave horse rebuild today so I can make gennou handles. I have a piece of wood from So to make the handle for the 300g Hiroki.

I don't know if mine will look as nice as Stan or Derek's though. I tend to finish my handles using a microplane that leaves a rougher pattern in the handle surface. Does this type handle benefit from a smoother surface?

[Stanley Covington]

Pat:

No wedges, no roughening, just a very tight compressed fit driven with many hard hammer blows. This is why the butt needs to be domed, or the handle may split from the butt.

Don't have anything to do with the silly practice of kigoroshi on gennou handles.

Stan

[Stanley Covington]

Thanks for the diagram Stan. I hope to finally finish my shave horse rebuild today so I can make gennou handles. I have a piece of wood from So to make the handle for the 300g Hiroki.

I don't know if mine will look as nice as Stan or Derek's though. I tend to finish my handles using a microplane that leaves a rougher pattern in the handle surface. Does this type handle benefit from a smoother surface?

I doubt you could make the curves with a plane unless it really is tiny. Spokeshaves work well for me. Sandpaper works well for finishing, too ......

Stan

[Mike Holbrook]

The Microplane I am referring to is not actually a plane but more of a rasp type tool. They may be as common in cooking as woodworking, used to grate food items like carrots. They have small razor sharp cutting surfaces. I have one that leaves a slightly rough/tacky texture on surfaces. I have used microplanes, Iwasaki, Gramercy and Auriou rasps on: axe,hammer,adze, carving tool...handles to leave a similar surface to the surfaces I find on Gransfors Bruks, Hans Karlsson, Svante Djarv, Swedish "Sloyd" carving tools. I use them after a drawknife and spokeshave rather than sandpaper to retain a rougher surface. I was not sure if a smoother surface might be an advantage with gennou as I have yet to see a handle for these tools left as rough as the Swedish tools often are.

[Stanley Covington]

Mike,

Thanks for clarifying both the tool and the intention. I have Gransfors Bruks hatchet and understand the " beaver gnawed" surface.

I think that would be too much for me, but whatever works best for you.

Stan