Dieter Schmid's Fine Tools
Genno -  Japanese Hammers

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.

Will be translated soon! Die viereckigen und achteckigen Hämmer haben auf der einen Seite des Hammerkopfes eine plane Schlagfläche, auf der anderen eine leicht ballige. Je nach Bedarf kann entweder die eine oder die andere Seite eingesetzt werden. Die plane Seite wird z. B. für das Schlagen von Stemmeisen benutzt oder für Eintreibarbeiten ganz dicht an Innenkanten von Werkstücken. Die Seiten des Hammerkopfes gleiten dabei über die Werkstückfläche wobei sich die Schlagfläche genau im rechten Winkel befindet. Damit ist die Chance einen kleinen Nagel an ungünstiger Stelle gerade eintreiben zu können erheblich erhöht. Beim Einschlagen von Nägeln mit Versenkung des Nagelkopfes verhindert man beim Verwenden der balligen Seite eine Beschädigung der umliegenden Holzoberfläche.

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.

Genno - square head, round edges
Head weight Total length CodePrice
115 g 30 cm
Code 309700CartPrice € 22.00
225 g 33 cm
Code 309703CartPrice € 24.00
375 g 33 cm
Code 309705CartPrice € 29.00
570 g 36 cm
Code 309707CartPrice € 38.00
750 g 37 cm
Code 309709CartPrice € 48.00

Genno - octagonal head
Head weight Total length CodePrice
115 g 30 cm
Code 309717CartPrice € 22.00
225 g 33 cm
Code 309720CartPrice € 24.00
375 g 33 cm
Code 309722CartPrice € 29.00
570 g 36 cm
Code 309724CartPrice € 37.00
750 g 37 cm
Code 309726CartPrice € 45.00
Genno steel, copper plated, square head, round edges
Head weight Total length CodePrice
225 g 33 cm
Code 309710CartPrice € 29.00
375 g 33 cm
Code 309712CartPrice € 36.00


Genno steel, copper plated, octagonal head
Head weight Total length CodePrice
225 g 33 cm
Code 309727CartPrice € 29.90
375 g 33 cm
Code 309729CartPrice € 38.00
Genno steel, copper plated and engraved square head, round edges
Head enlarged
Head weight Total length CodePrice
570 g 36 cm
Code 309749CartPrice € 79.00
Sakikiri - Pin Hammer or Nail Hammer Enlargement and more information
Mainly used to drive nails.
Head weight Total length CodePrice
125 g 30 cm
Code 309741CartPrice € 24.00
275 g 33 cm
Code 309743CartPrice € 26.00
Daruma - Japanese Sledge Hammer enough power to drive all kind of chisels!
Head weight Total length CodePrice
225 g 33 cm
Code 309734CartPrice € 24.00
375 g 33 cm
Code 309736CartPrice € 28.00
570 g 33 cm
Code 309738CartPrice € 37.00
Replacement Handles for Japanese hammers, made of white oak
For
hammer
weight
Dia-
meter
at side
of head
Length CodePrice
225 g 22 x 9 mm 330 mm
Code 309752CartPrice € 6.90
375 g 25 x 10 mm 330 - 360 mm
Code 309754CartPrice € 7.50
750 g 32 x 12 mm 360 mm
Code 309758CartPrice € 8.50

Hand forged hammers by Master Hiroki

Meister Hiroki bei der Arbeit

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.

Four-sided Orthodox Hammer 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 CodePrice
75 g 33 cm
Code 310700CartPrice € 89.00
95 g 33 cm
Code 310701CartPrice € 89.00
115 g 33 cm
Code 310702CartPrice € 89.00
150 g 33 cm
Code 310703CartPrice € 93.00
185 g 33 cm
Code 310704CartPrice € 95.00
225 g 36 cm
375 g 36 cm
Important advice:
The hammer comes disassembled. 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. Wedge not 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.
Orthodox Hammer "Daruma" 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 CodePrice
115 g 33 cm
Code 310722CartPrice € 99.00
225 g 36 cm Currently not in stock!
Code 310725Cart Price € 109.00
375 g 36 cm
Important advice:
The hammer comes disassembled. 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. Wedge not 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.
Orthodox Hammer "Yamakichi" 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 CodePrice
225 g 36 cm
Code 310730CartPrice € 135.00
300 g 36 cm
Code 310731CartPrice € 145.00
Important advice:
The hammer comes disassembled. 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. Wedge not 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.
Hammer wedge
Hammer Wedge Size 15 x 5 x 3 mm
Suitable for Hiroki hammers
Code 310739CartPrice € 3.50
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