The ball beads used are mostly made of stainless steel or cemented carbide. The size of the ball diameter determines the thickness of the line of the handwriting. Common ball diameters are 1 mm, 0.7 mm, and 0.5 mm (often written on the pen or ballpoint pen of the product). The ink of the ballpoint pen is specially made, mainly composed of a mixture of coloring materials, solvents and viscosity modifiers. Common colors are blue, black and red. Ordinary inks are mostly used for general writing, and special inks are often used for file writing. For the ink used for file writing, the mark is generally marked with a mark. For example, the domestic refill has the word DA.
The oily ballpoint pen is the first generation of the ballpoint pen series. It has been on the market for more than 60 years. After long-term improvement and improvement, the oily ball-point pen production process is mature, the product performance is stable, the storage period is long, the writing performance is stable, and it has become a traditional product variety in ball-point pen products. The ink used in the oil-based ball-point pen has high viscosity, so the writing feel is relatively heavy.