Sakai cutlery Photo:Osaka Prefecture

Sakai cutlery Sakai uchihamono

Only the finest edge selected by professional chefs
Strength produced by traditional craftsmanship

Description

Sakai Traditional Blades are hammer-forged and produced in Osaka Prefecture centering on the cities of Sakai and Osaka.
To achieve both strength and cutting quality, the blades are made by combining two different metals: soft iron and steel. The key features of Sakai Traditional Blades are the outstanding “forging” by the skilled craftsmen and the “sharpness” of the keen-edged blade. In recent years, the production of kitchen knives stamped out from a steel plate, with a sharpened edge section has been increasing; in contrast, Sakai Traditional Blades are made by hammering two different types of metal and finishing to a final blade shape. Knives forged in this traditional way have excellent hardness and a long lasting edge.
The production of blades can be broadly divided into three distinct stages –blacksmithing, sharpening, and attaching the handle – and to maintain the highest quality, this division of tasks, one of the key features of Sakai Traditional Blades, is still carried out to this day. There are a broad range of knife shapes and sizes according to the intended purpose, and it is said that more than 90% of knives used by chefs are Sakai Traditional Blades.

History

In Sakai City and its environs, a large number of ancient mounds are found including the largest keyhole-shaped Japanese burial mound, the mausoleum of Emperor Nintoku, which is believed to have been constructed in the Kofun (Tumulus) period. In those days, to construct a burial mound, large numbers of spades, hoes, and tools were manufactured to enable such massive engineering works. The blacksmiths who had produced the tools established a settlement in Sakai and continued to develop their skills to make tools and swords.
In 1543, the Portuguese introduced guns and tobacco into Japan and around this period, Sakai with its highly-skilled metal workers naturally became a major center for the manufacture of firearms, especially toward the end of the Warring States period (1467-1568).
With the coming of the more settled Edo period (1603-1867), the demand for firearms decreased, but smoking became popular, giving rise to a need for tobacco leaf cutting knives. The tobacco knives made by the craftsmen of Sakai were of an outstanding quality and people knew them to be better than imported knives; the Tokugawa Shogunate went on to hallmark them as a government monopoly with a seal bearing the words Sakai Kiwame, and their reputation soon spread throughout Japan.
Later with the introduction of machinery to tobacco production, demand for tobacco knives fell, but craftsmen took advantage of their well-honed skills and started producing knives suitable for catering and gained much support from professional chefs.

General Production Process

  1. 1. Steel Welding Steel coated with boric acid, borax, and iron oxide powder is laid upon red heated soft iron and softened in a furnace at about 900ºC. The two metals are hammered to bond and create an iron and steel plate ready to be the base of a blade.
  2. 2. Shaping The flattened iron is reheated to about 600 to 700ºC and hammered out repeatedly to thin the metal; the iron and steel are fused and the rough shape of a knife created. Excess metal is cut off and the tang for the handle also cut to shape.
  3. 3. Annealing The shaped knife is put to rest on a bed of straw and left to naturally cool down. The slow cooling and the straw becoming ash helps remove internal distortions.
  4. 4. Rough Hammering To flatten out hammer marks and tiny holes left from shaping, the blade surface cooled to a room temperature is now hammered. Rough hammering beats out impurities, tempers the blade, straightens any distortion, and creates a uniform thickness.
  5. 5. Cutting The knife is placed on a cutting guide and all excess metal is cut off.
  6. 6. Grinding After adjustment of distortions, an impression is made on the reverse side. Rough edges caused by cutting and excess metal is smoothed off, and the entire surface is finished with a grinder. The knife is also hammered to rework any distortion.
  7. 7. Mud Coating The knife is coated with mud to prevent uneven heating and ensure quick and even cooling during tempering. First any oil or remaining dirt is removed, and then the mud is applied and left to dry near the furnace.
  8. 8. Tempering Rapid cooling changes the molecular constituency of metal and makes it harder. The process is very basic, the knife is heated to 750 to 800ºC and straightaway plunged into cold water. The tempered knife is heated again to 180 to 200ºC and allowed to cool naturally; this increases the blade’s viscosity and strength, and helps prevent chipping. To judge the right temperature, water droplets are splashed onto the blade and the craftsman by watching how they run, knows when to stop heating; this requires much skill and experience.
  9. 9. Polishing Giving an edge or polishing turns good steel from being simply a metal sheet into a knife; the sequence is rough polishing, fine polishing, reverse side polishing, hazing, and final polishing.
    • Rough polishing: Although named rough, this first polishing is an important process as it determines the angle of the blade edge. During rough polishing, any revealed distortion is diligently checked.
    • Fine polishing: The blade edge continues to be worked and any scratches and distortions resulting from rough polishing are polished out along with adjusting the blade thickness. In this stage as well, any distortion is checked.
    • Reverse side polishing: The reverse side of the blade is also lightly polished. By increasingly finer polishing, scratches are removed and any distortion is checked.
    • Hazing: Kneaded whetstone powder is rubbed on the knife blade, giving the iron a flat subdued color and shining the steel; this clear border between the iron and steel helps show off the beauty of the knife.
    • Final polishing: A very fine whetstone is used to carefully polish and finish the blade with a razor keen edge of the highest quality ready to be fitted with a handle.

Where to Buy & More Information

Sakai Traditional Crafts Museum