Genno - Japanese Hammers
Genno - that’s what the Japanese call these hammers. A whole page has been devoted to it not so much because of its function but because of its origin, for it has a quite individual character. The selective hardening of the actual hammering surfaces means that part of the recoil energy is absorbed by the slightly softer core. While one is hitting the work with the hammer one has the feeling that the stroke is more effective, and the reason is that less recoil affects the wrist.
In Japan, metal hammers are traditionally used even to hammer chisels; the right one for this is the 375 g hammer. It will of course be necessary to aim rather more precisely than with the wooden block. If you feel somewhat nervous of trying this, the Daruma should do the trick. It is an impressive hand hammer with a broad enough surface.
The hand forged hammers made by Master Hiroki are well-balanced, the handle is ergonomically formed and it is a pleasure to work with these masterpieces.
Click on the pictures for enlargements!
Picture left
| Head weight | Total length | Order nr. | Price |
|---|---|---|---|
| 115 g | 30 cm | 309700  |
€ 15.90 |
| 225 g | 33 cm | 309703 |
€ 18.90 |
| 375 g | 33 cm | 309705 |
€ 21.90 |
| 570 g | 36 cm | 309707 |
€ 29.90 |
| 750 g | 37 cm | 309709 |
€ 35.90 |
Genno - octagonal head
Picture right
| Head weight | Total length | Order nr. | Price |
|---|---|---|---|
| 115 g | 30 cm | 309717 |
€ 15.90 |
| 225 g | 33 cm | 309720 |
€ 18.90 |
| 375 g | 33 cm | 309722 |
€ 21.90 |
| 570 g | 36 cm | 309724 |
€ 29.90 |
| 750 g | 37 cm | 309726 |
€ 35.90 |
Picture left
| Head weight | Total length | Order nr. | Price |
|---|---|---|---|
| 225 g | 33 cm | 309710 |
€ 21.90 |
| 375 g | 33 cm | 309712 |
€ 27.90 |
Genno steel, copper plated, octagonal head
picture right
| Head weight | Total length | Order nr. | Price |
|---|---|---|---|
| 225 g | 33 cm | 309727 |
€ 21.90 |
| 375 g | 33 cm | 309729 |
€ 27.90 |
square head, round edges
Head enlarged
| Head weight | Total length | Order nr. | Price |
|---|---|---|---|
| 225 g | 33 cm | 309745 |
€ 49.90 |
| 375 g | 33 cm | 309747 |
€ 59.90 |
| 570 g | 36 cm | 309749 |
€ 65.90 |
Enlargement and more information
Mainly used to drive nails.
| Head weight | Total length | Order nr. | Price |
|---|---|---|---|
| 125 g | 30 cm | 309741 |
€ 17.90 |
| 275 g | 33 cm | 309743 |
€ 21.90 |
Hand forged hammers by Master Hiroki
In Japan, carpenters were traditionally paid by the number of finished joints. In order to work quickly, they needed perfectly-balanced hammers. As Japan modernized, the manufacture of these kinds of hammers was mostly forgotten. But the art and tradition lived on through the 20th century in the person of master smith Kozaburo Hasegawa. He died in 2004.
Master smith Aida Hiroki has followed in his footsteps and is thought to be the only smith left manufacturing these fine hammers according to the principles of centuries of tradition. Hiroki sells the hammers under the trademark of Aitoyo. The hammers are known as "orthodox" hammers, in accordance with the original meaning from the Greek: the correct, straight-line teaching or tradition, and so Hiroki shows his admiration for the skills and methods developed by the centuries of hammer smiths that preceded him.
There are many steps in the process of forging a hammer head. But making the hole to take the handle is the most complicated and demanding. First one hammers a small hole most of the way through the red-hot head blank. This hole, which at first does not go completely through the hammer, deforms the head. Therefore the head is corrected again and again as the hole is enlarged. This process is done by sight, by feel and by intuition. Hiroki takes no measurements and relies on a lifetime of experience. If the hole is not perfectly centered, the thin side is cooled a bit with water, and the head is brought with some well-placed hammer blows into balance. Seen first hand, it is a virtuoso performance -- forging red hot steel like a baker forms dough. It is also important to keep sharp interior corners in the hole, so that the handle can be fixed as securely as possible. Short Video
By selective water tempering, Hiroki reduces the hardness of the steel inside the hammer's head. This eliminates the chance of the head breaking, and lessens the stress on the hand and wrist, since the full force of the impact cannot travel up the handle. The hammer head is not laminated, it is made of one piece of high-carbon steel.
This hammer is four-sided with rounded edges. One striking face is flat, and the other is slightly convex. A hammer is well-balanced when, without a handle, it can be stood up on its convex end. The handle is ergonomically formed for right handers. In the grip it is in the form of a lightly rounded triangle, and so lays wonderfully in the hand. Enlarged photos and a look at Master Hiroki at work
| Head weight | Total length | Order nr. | Price |
|---|---|---|---|
| 75 g | 33 cm | 310700 |
€ 68.00 |
| 95 g | 33 cm | 310701 |
€ 68.00 |
| 115 g | 33 cm | 310702 |
€ 68.00 |
| 150 g | 33 cm | 310703 |
€ 69.00 |
| 185 g | 33 cm | 310704 |
€ 71.00 |
| 225 g | 36 cm | 310705 |
€ 73.00 |
| 375 g | 36 cm | 310707 |
€ 79.00 |
Important advice:
The hammer comes with the handle only roughly fitted. One must finish shaping the handle with a plane, chisel, file or rasp (there are many methods, use the one that works the best for you) to achieve the best fit possible. A small wedge is included. Removing hammer head
Master Hiroki is of the opinion that if the handle is properly fitted, a wedge is not necessary. If one wants to follow this "Orthodox" advice, one does so at one's own risk.
This hammer is round, with a more compact body and a wider face. One face is flat, and the other slightly convex. The handle is a lightly rounded rectangle. In use the hammer lies very well in the hand, feeling more like one's own fist than any ordinary hammer. Enlargement and detailed pictures
| Head weight | Total length | Order nr. | Price |
|---|---|---|---|
| 115 g | 33 cm | 310722 |
€ 74.00 |
| 225 g | 36 cm | 310725 |
€ 79.00 |
| 375 g | 36 cm | 310727 |
€ 85.00 |
Important advice:
The hammer comes with the handle only roughly fitted. One must finish shaping the handle with a plane, chisel, file or rasp (there are many methods, use the one that works the best for you) to achieve the best fit possible. A small wedge is included. Removing hammer head
Master Hiroki is of the opinion that if the handle is properly fitted, a wedge is not necessary. If one wants to follow this "Orthodox" advice, one does so at one's own risk.
The very lightly convex face and a chisel point behind makes this an ideal hammer for driving nails but also good for many other uses. The handle is ergonomically designed in the shape of a rounded right triangle and fits very nicely in the hand. Enlargement and detailed pictures
| Head weight | Total length | Order nr. | Price |
|---|---|---|---|
| 225 g | 36 cm | 310730 |
€ 92.00 |
| 300 g | 36 cm | 310731 |
€ 95.00 |
Important advice:
The hammer comes with the handle only roughly fitted. One must finish shaping the handle with a plane, chisel, file or rasp (there are many methods, use the one that works the best for you) to achieve the best fit possible. A small wedge is included. Removing hammer head
Master Hiroki is of the opinion that if the handle is properly fitted, a wedge is not necessary. If one wants to follow this "Orthodox" advice, one does so at one's own risk.
