Advice on a Gennou Hammer?

[onocoffee]

A few month ago, when my brother was in Tokyo, I asked him to swing by Inoue Hamono and pick me up a Kanna. I've had it now since he returned and just haven't gotten around to setting it up - honestly, I've been a bit intimidated, but now I'm ready.

I wanted to get a gennou hammer for the kanna and chisels but the problem is that with the US tariff and postal service issues, many businesses in Japan (including Inoue Hamono) have suspending shipments to the USA. I even messaged Inoue-san to see when it might resume and he has no idea. So I've been looking at a Shinwa gennou at my local Woodcraft wondering if it's good enough. I'm familiar with Shinwa and have some of their measuring tools, so I feel reasonably sure their quality is going to be decent. Just would like to get a nice one so I can try to not have 64 gennous down the road

From what I've read, I think 375g is a good starting weight? Any thoughts will be appreciated. Thanks!

 

[Packard]

I had no idea what a Gennou hammer is. I still don’t know what makes it special. All I found out is that it is Japanese and requires a special handle.

I have a 50 year old auto body hammer that has a similar face. What’s the difference?

 

[ChuckS]

A few month ago, when my brother was in Tokyo, I asked him to swing by Inoue Hamono and pick me up a Kanna. I've had it now since he returned and just haven't gotten around to setting it up - honestly, I've been a bit intimidated, but now I'm ready.

I wanted to get a gennou hammer for the kanna and chisels but the problem is that with the US tariff and postal service issues, many businesses in Japan (including Inoue Hamono) have suspending shipments to the USA. I even messaged Inoue-san to see when it might resume and he has no idea. So I've been looking at a Shinwa gennou at my local Woodcraft wondering if it's good enough. I'm familiar with Shinwa and have some of their measuring tools, so I feel reasonably sure their quality is going to be decent. Just would like to get a nice one so I can try to not have 64 gennous down the road

From what I've read, I think 375g is a good starting weight? Any thoughts will be appreciated. Thanks!

375 g is what is usually recommended, but I really enjoy mine of 225g (edit: the scale says 340 g including the handle. So mine should be 225g or lighter, not 300g as previously stated). The pounding is strong enough for all chisel work, and it is not overly heavy for hammering for an extended period of time. I've used it for a decade and would recommend it for detailed and precision work.

 

[derekcohen]

A few month ago, when my brother was in Tokyo, I asked him to swing by Inoue Hamono and pick me up a Kanna. I've had it now since he returned and just haven't gotten around to setting it up - honestly, I've been a bit intimidated, but now I'm ready.

I wanted to get a gennou hammer for the kanna and chisels but the problem is that with the US tariff and postal service issues, many businesses in Japan (including Inoue Hamono) have suspending shipments to the USA. I even messaged Inoue-san to see when it might resume and he has no idea. So I've been looking at a Shinwa gennou at my local Woodcraft wondering if it's good enough. I'm familiar with Shinwa and have some of their measuring tools, so I feel reasonably sure their quality is going to be decent. Just would like to get a nice one so I can try to not have 64 gennous down the road

From what I've read, I think 375g is a good starting weight? Any thoughts will be appreciated. Thanks!

I would not purchase a 375g gennou head unless you intend it for mortising into hard, hard wood. My preference for a bench chisel (oire nomi) is 225g. For a plane hammer, the 150g.

Also, the guy in the video has no clue about gennou handles. Here are a couple of mine ...



To give you an idea of a 150g, see the one at the bottom ...



The middle gennou is a modified 225g head with a short handle for my travel tool box.

A pictorial on my website: https://www.inthewoodshop.com/ShopMadeTools/AHandleforaGennou.html

Regards from Perth

Derek

 

[onocoffee]

Thank you, @derekcohen

I actually came across the page you liked after I posted this thread and was searching on Wilbur Pan's blog. In one of the articles, he mentioned your name and linked to that page and I remember thinking "Oh, I know that guy - I hope he sees this thread!"

I realize you're Down Under but any thoughts on sourcing? Like I said, the shop I would have ordered has suspended shipping to the USA, so I'm left with what's here - and I really don't know anything about where and who to source from. I did send an IG message to one of the Japanese tool purveyors a couple weeks ago about a gennou but no response.

After listening to a Shop Talk Live with Wilbur, I took his advice to heed on "letting the tool master guide you" - which is why I let Inoue-san guide me into the kanna. So, I'm open to guidance here.

What I have available to me is a Woodcraft and they have a couple of Shinwa gennou in 375g (13oz) and one that's listed as 4z (which I think is 113g):

https://www.woodcraft.com/search?view=products&options%5Bprefix%5D=last&q=hammer

I do currently own the FastCap Artisan Finishing Hammer (4z) that looks to be of the Japanese style.

FastCap Artisan Finishing Hammer, 4oz

FastCap 4 oz. Artisan Hammer is a little wonder. It is just the right size for driving small brads, setting escutcheon pins, tapping in dowel plugs, or a m

www.woodcraft.com

Thanks!

 

[onocoffee]

I had no idea what a Gennou hammer is. I still don’t know what makes it special. All I found out is that it is Japanese and requires a special handle.

I have a 50 year old auto body hammer that has a similar face. What’s the difference?

I'm certainly not one to quote on this - because what I know is very limited and very topical. However, what I've surmised is that the gennou has a flat head on one side and a rounded head on the other. For what specific purposes? I've heard the reasons but they have not embedded themselves into my understanding and comprehension yet.

I'm also thinking that the gennous are what I've heard termed as "pre-industrial revolution" type of tools - meaning hand hammered and layered (perhaps like the chisels) as opposed to modern alloys - and I'll stop there because I really don't know what I'm talking about!

 

[Imemiter]

I've been trying out an engineer's mallet. One day, chiseling a hinge plate (probably,) I didn't have anything to use but a dead-blow hammer. Surprisingly, it didn't blow. I actually liked the control, but even my smallest DB was too big, so I got myself this PB Swiss for Christmas. I've only tried it in the shop so far, so we'll have to see if it makes it into my EDC.

 

[bertv]

What Derek says —- use the lighter gennou, or a small wooden hammer.

 

[Packard]

This is the type of hammer I have. I got it and an auto body dolly to hammer out damage to my Alfa Romeo. It was just parking lot damage, but the dealer wanted a fortune to repair it.

Because of the tight radii to the fenders, the steel was very soft and easy to hammer out. In any case, I have had it since 1969, and still use it to strike my chisels when cutting mortises. A very light hammer with a generous face. The one in the image is 12 ounces, and that sounds about right for mine too.

 

[derekcohen]

Thank you, @derekcohen

I actually came across the page you liked after I posted this thread and was searching on Wilbur Pan's blog. In one of the articles, he mentioned your name and linked to that page and I remember thinking "Oh, I know that guy - I hope he sees this thread!"

I realize you're Down Under but any thoughts on sourcing? Like I said, the shop I would have ordered has suspended shipping to the USA, so I'm left with what's here - and I really don't know anything about where and who to source from. I did send an IG message to one of the Japanese tool purveyors a couple weeks ago about a gennou but no response.

After listening to a Shop Talk Live with Wilbur, I took his advice to heed on "letting the tool master guide you" - which is why I let Inoue-san guide me into the kanna. So, I'm open to guidance here.

What I have available to me is a Woodcraft and they have a couple of Shinwa gennou in 375g (13oz) and one that's listed as 4z (which I think is 113g):

https://www.woodcraft.com/search?view=products&options%5Bprefix%5D=last&q=hammer

I do currently own the FastCap Artisan Finishing Hammer (4z) that looks to be of the Japanese style.

FastCap Artisan Finishing Hammer, 4oz

FastCap 4 oz. Artisan Hammer is a little wonder. It is just the right size for driving small brads, setting escutcheon pins, tapping in dowel plugs, or a m

www.woodcraft.com

Thanks!

One of the most knowledgable woodworkers on Japanese tools I know, as well as one of the friendliest - and he sells the best, most cost-effective tools - is Stanley Covington. He is an American based in Japan.

Covington & Sons Tools

Information about using and maintaining woodworking tools, especially Japanese chisels, planes and handsaws

covingtonandsons.com

Not only will he advise on the best in your price range, but will procure it for you. Stan did not an issue with my article, which I have since rectified on my own gennou, just not bothered on the website - the handle should not protrude through the gennou head. It should be flat.

Why do I like using a gennou compared with a claw hammer? the gennou is the right weight, is compact and direct energy where it is needed, is made of a core of softer steel to absorb vibrations that cause RSI .. and looks cooler

Regards from Perth

Derek

 

[thudchkr]

I picked up both the 375 g and the 225 g from fine-tools.com, https://www.fine-tools.com/Genno-Corners-Rounded/309700-main, that I've been happy with.

I also acquired the following Zen-Wu hammer from Katz-Moses, https://kmtools.com/products/zen-wu-f-2-hammer-damascus-steel . I really like the Damascus steel construction, but find the supplied handle to be inordinately long. I plan on shortening the handle or making a new one at some point, but in the meantime typically grab one of the genno from fine-tools.com

Clint

 

[onocoffee]

One of the most knowledgable woodworkers on Japanese tools I know, as well as one of the friendliest - and he sells the best, most cost-effective tools - is Stanley Covington. He is an American based in Japan.

Covington & Sons Tools

Information about using and maintaining woodworking tools, especially Japanese chisels, planes and handsaws

covingtonandsons.com

Not only will he advise on the best in your price range, but will procure it for you. Stan did not an issue with my article, which I have since rectified on my own gennou, just not bothered on the website - the handle should not protrude through the gennou head. It should be flat.

Why do I like using a gennou compared with a claw hammer? the gennou is the right weight, is compact and direct energy where it is needed, is made of a core of softer steel to absorb vibrations that cause RSI .. and looks cooler

Regards from Perth

Derek

Thank you, Derek. I have reached out to Stanley.

 

[Mini Me]

This is the type of hammer I have. I got it and an auto body dolly to hammer out damage to my Alfa Romeo. It was just parking lot damage, but the dealer wanted a fortune to repair it.

Because of the tight radii to the fenders, the steel was very soft and easy to hammer out. In any case, I have had it since 1969, and still use it to strike my chisels when cutting mortises. A very light hammer with a generous face. The one in the image is 12 ounces, and that sounds about right for mine too.

View attachment 380532

That is a planishing hammer.

 

[Packard]

That is a planishing hammer.

For me, it is a light weight do-everything hammer. I’ve had it for 55 years (roughly 7-1/2 times the average length of a first marriage in the USA).