I found out the hard way that making what seems to be a simple knife, is not so simple. Traditionally, Japanese knives were single bevel, and featured the same grind with three key parts: the shinogi surface, the urasuki, and the uraoshi. It wasn’t until Japan began modernizing in the late 19th century and early 20th century — and when they began incorporating western culture in to theirs — that they started crafting double beveled knives. The Japanese have continued to forge beautiful, sharp, and strategically designed single-edged knives that make slicing and dicing more efficient for any chef. To better understand how this is done, let’s explain the anatomy of a single-edged knife:
The Japanese are known for their culinary expertise and skills with knives. The very art of sushi alone requires a skilled chef, but in order to achieve the correct cuts of vegetables and fish, the proper tool is required. Many single-edged knives are perfect for chopping vegetables thinly and quickly, making the chef’s job easier. Above we discussed the brief definitions of the different aspects that make a single-edged blade, but below we’ll discuss their importance and use.
Shinogi Surface The shinogi surface is the flat surface of the blade that runs to the blade’s edge in a single-bevel knife. This flat surface allows for a narrow blade angle, resulting in a sharper knife. The second you add another bevel to the shinogi surface — which would essentially make it a double-edged blade — you also effectively make the blade not as sharp. The geometry of the shinogi surface allows for an almost razor-like edge. Urasuki The urasuki is the concave surface on the backside of the blade that creates an air pocket when the blade is slicing through food. This helps to reduce drag and creates a smoother surface, so you can make faster, nicer cuts. It also works to prevent the food from sticking to the knife. The image below shows the air pocket created by the urasuki while cutting. The combination of the urasuki and shinogi allow for the blade to cut food with very minimal damage to the surface and cells, therefore not spoiling the texture and taste. Uraoshi The uraoshi is the thin, flat rim that surrounds the urasuki. Its purpose is to enhance the strength of the blade at its otherwise vulnerable edges.