January 2005. MITSUBISHI PENCIL (三菱鉛筆). 0.18mm in ball diameter. PILOT CORPORATION (パイロット) put the finest ballpoint pen in the world, 0.13mm in width of line, on the market, in March 2004, the year before. The pen point is super-hard and 0.23mm in diameter, and super-minute-grain biotechnology Polymer ink is used. The ballpoint pens of 0.15mm in width of line were manufactured 100 million or more, and sold the most in the world.