steel balls are divided into grinding steel balls, forging steel balls and casting steel balls according to the production and processing technology. According to the processing materials, it is divided into bearing steel balls, stainless steel balls, carbon steel balls, copper bearing steel balls and alloy steel balls. Among them, bearing steel ball is an important basic part of industry, and alloy steel ball is a kind of spherical ferroalloy wear-resistant body with carbon, chromium, manganese and molybdenum as the main metal elements, which is produced by forging, spinning, rolling and casting. Steel ball is a kind of metal abrasive, and its main varieties are stainless steel shot, cast steel shot, aluminum shot, steel wire cutting shot, grinding shot and copper shot.
a patent literally refers to the exclusive rights and interests. The word "patent" comes from Latin Litteraepatentes, which means open letters or public documents. It is a certificate used by medieval monarchs to issue certain privileges, and later refers to the exclusive rights certificate signed by the British king himself.