These Carbide Mircro Drill Bits are from the Union Company in Japan. We aquired them through our distributer in South Korea where our business was based. They are of the highest quality. All bits are 18 inch 3.175mm shank. Many Uses: Toy making Model Cars, trains, trucks, boats Jewelry making CNC Circuit board production Hobbies Woodworking Soft Metals Arts and crafts Installation more.