Japanese hammer/genno

[Derek Cohen]

There is an article on making handles for a gennou on my website: http://www.inthewoodshop.com/ShopMad...oraGennou.html

Those handles were eventually remade a couple of times until I achieved a comfortable diameter. The current two I use are …



375g (upper) and 225g (lower) heads. I use the 225 mostly, and the 375 when morticing.

Regards from Perth

Derek

[Halgeir Wold]

Excuse my 'ignorance' - but up here way above the 'moral' ( arctic) circle, most people I know haven't heard of japanese tools, neither seen a picture of one..
I have had my pull saws for quite some time, and I'm concidering buying a few wide chisels... but except for 'coolness' , what's so special about the gennou hammers?? While I fully understand the weight and balance thing, which also applies to other types of tools, what is it about these hammers? Hardening of the head? Other aspects??

[Derek Cohen]

This is a quote from So Yamashita’s website. So lives on the northern beaches of Sydney and sells the very highest quality Japanese tools. I obtained my gennou heads from him many years ago.

A bit more on Japanese hammers, since I started (^^). Top quality handmade Japanese hammerheads are not hardened just evenly throughout the body. The hardness is different within a single head. The centre of the striking surface is softer so that it won't be as slippery when striking the nail. The peripheral is made harder to prevent dents and chips. The body is hardened and tempered to make it as tenacious as possible to absorb the shock. The best of the best hammerheads are constructed using soft iron for the body and steel laminated on the striking surface. The MOST expensive ones even have wood grain pattern on the jigane (body iron). The handle attatching hole is opened to absolute square, and the center is made slightly tighter by tapping the body from outside after the hole has been gouged. This makes it possible for the handle to be attatched with no wedge holding the handle from the other side, and still will not come off. The best made hole's edge is not rounded at all, and it looks as if it was chiseled out.


Japanese gennous aren't just a chunk of steel with a hole in the middle. It has a microcosm in itself.ore on
Japanese hammers, since I started (^^). Top quality handmade Japanese hammerheads are not hardened just evenly throughout
Regards from Perth

Derek

A bit more on Japanese hammers, since I started (^^). Top qualitping the body from outside after the hole has been gouged. This makes it possible for the handle to be attatched with no wedge holding the handle from the other side, and still will not come off. The best made hole's edge is not rounded at all, and it looks as if it was chiseled out.

Japanese gennous aren't just a chunk of steel with a hole in the middle. It has a microcosm in itself.

[Reed Gray]

I was wondering what the weight was, and the heavier one above is about a pound. That would be adequate, and not too heavy. I picked up a set of carving chisels which had a persimmon mallet with them. It is about 4 inch diameter and just too heavy. When doing concrete construction, I started with a 32 oz. hammer. I ended up with a 20 oz. hammer. That is just too much weight to be swinging around, except for driving stakes. 10 pound sledge....

I am curious about what weights you all prefer????

robo hippy

[Cameron Wood]

Here are mine. Left: In use 3 months, (requested) gift. From Kakuri (Amazon or direct), recommended for good middle quality Japanese tools. This is the highest end one 375g. I was intending to make a new handle a la Stan Covington, but the stock one was well attached, so I modified it. Was wanting to get the next heavier size and it feels heavier, but turns out same weight as #2. The favorite. Second: In use 30+ years, Dogyu? Third: In use 10+ years, but light duty in the work truck closing paint cans, etc. I agree with Covington that this style, while popular, is less useful overall. Forth: good for detail work. Fifth: saw set. Sixth: carpentry hammer that I used years ago. Weight good, but face too flat, handle skinny, claw pretty useless and makes it ride poorly in a hammer loop.
First post BTW.


IMG_3540.jpg

[Jim Koepke]

Howdy Cameron and welcome to the Creek.

jtk

[Cameron Wood]

Howdy Cameron and welcome to the Creek.

jtk

Thanks! My first name is Jay but in the course of an epic struggle to register on the site, I used my middle name.

[Christopher Charles]

Step away, step away from the slippery slope...

(I have a couple gennou, including one from Stan. Making a handle that fits your hand makes a big difference. The japanese hammers do have a noticeably lower amount of 'bounce' if you let them drop while holding onto a board, does which translates to more force being transferred. In reality, it is subtle, but my sweet little Hiroki is one of the last bits of bench jewelry I'll ever part with.)

IMG_0832.jpg

[William Fretwell]

I agree about the handle. Here is mine with the handle I made and the discarded handle it came with.
E7A73D2C-772D-4F05-B1C1-92151690DA84.jpg
The difference in use is like night and day.

[Cameron Wood]

Thanks.

My first name is Jay but an epic struggle registering for the site led to using my middle name.

[Keegan Shields]

This is a quote from So Yamashita’s website. So lives on the northern beaches of Sydney and sells the very highest quality Japanese tools. I obtained my gennou heads from him many years ago.

A bit more on Japanese hammers, since I started (^^). Top quality handmade Japanese hammerheads are not hardened just evenly throughout the body. The hardness is different within a single head. The centre of the striking surface is softer so that it won't be as slippery when striking the nail. The peripheral is made harder to prevent dents and chips. The body is hardened and tempered to make it as tenacious as possible to absorb the shock. The best of the best hammerheads are constructed using soft iron for the body and steel laminated on the striking surface. The MOST expensive ones even have wood grain pattern on the jigane (body iron). The handle attatching hole is opened to absolute square, and the center is made slightly tighter by tapping the body from outside after the hole has been gouged. This makes it possible for the handle to be attatched with no wedge holding the handle from the other side, and still will not come off. The best made hole's edge is not rounded at all, and it looks as if it was chiseled out.

Here is a sincere question, not intended to offend, for those most familiar with Japanese tools - how much of this is marketing B.S.?

I've always wondered, as the descriptions are beautifully written. Japanese culture has a lot of ceremony/ritual incorporated in it and Shinto traditions that give inanimate objects attributes that probably don't have an equivalent in Western culture.

I appreciate true craftsmanship and don't want to discount the skill involved. But these are businesses all selling essentially the same widgets. Do these product features actually make a difference in performance? Perhaps whoever wrote this took some creative license with the copy? Is this just ritual for the sake of marketing?


I recall a blind test of professional violinists playing both modern violins and Stradivarius violins. When asked to choose the best sounding violins, most unknowingly choose the modern versions. But most were still convinced that the Strats were better.


Is my skepticism unwarranted here?

[Phil Cyr]

I think a gennou is actually better, but perhaps the best feature of a well crafted head is that it inspires you to create a well crafted handle. I have never gone out of my way to make a good handle for a random hammer head, but I have spent the time to make a handle for my gennou that fits my hand and arm. It is so much easier to use than any other hammer I have ever had.

[Cameron Wood]

I think there is marketing, tradition, and like high-end things generally, at the top the performance difference is vanishingly small.
The best is not always the best, however- for example high end saws have brittle teeth that are easily broken. Your Ferrari is not ideal as a grocery getter.
I have generally mid and upper-mid quality tools, and quite a few used ones that were clearly good enough to have been used professionally for many years, and sharpened hundreds of times. So much depends on the set up and tools kind of have their individual personalities so one learns how to get the best from them. Compared to normal western tools, 'tho, one chisel is used for precise joinery, and the other is mostly used for scraping glue. The metal planes have their good points but rarely get used, & the only western saw that gets used is a hacksaw.

[Ed Hilton]

Those handles were eventually remade a couple of times until I achieved a comfortable diameter. The current two I use are …


Derek

With the butt end of the handle larger than the head end, how is the head secured?

[Derek Cohen]

Ed, go here for a pictorial I wrote:

http://www.inthewoodshop.com/ShopMad...oraGennou.html

Regards from Perth

Derek