Depending on the size of the particles, the whetstone is divided into three types: "Arato"(rough), "Nakato" (middle), and "Shiageto" (finish). There are also natural whetstone and artificial whetstone.
The artificial whetstone began production in the 19th century United States. It is currently widely circulated because it is homogeneous and easy to purchase.
Natural whetstones are still popular because the "Atari" (the comfortability of the whetstone and workpiece when sharpening) on bladed objects is soft.
The raw materials of natural whetstone are mainly sedimentary rock and tuff. "Arato" is made of sandstone, and "Siaghetto" is made of fine-grained mudstone and slate. Sedimentary rocks deposited with the quartz skeleton of Radiolaria are recognized as good quality.
The raw materials for the artificial whetstone are mainly aluminum oxide and silicon carbide, and it is divided into several characteristics according to the preparation additives. Besides that, diamonds, CBN, and garnet are also used as raw materials.
Whetstones are mainly used to improve the cutting function when the sharpness of a metal blade is reduced. There are also many kinds depending on the application.
Although it is a tool that has been used since the beginning of humankind, it has been widely used in modern times because it can obtain machining accuracy that cannot be obtained by cutting tools.
The whetstone is classified into factors such as the kind of the components, the particle size (roughness of the ingredient), the degree of binding (the force to bind the components), the texture (density of the ingredient), and the binder (Materials for solidifying powder raw materials).
All metals or nonmetals can be precisely sharpened.
Comparison of Natural Whetstones to Artificial Whetstones