What do the subtitles on centerless grinder models mean?

I seem to have answered this question before. The letter represents the centerless grinder. M means grinder. A B C is the model they improve every time. A means one improvement. If there is no letter after it, it means the new product is under trial.

Another way of expressing it is that of Dongguan Hartmann Hardware Technology Co., Ltd.

For example, the centerless grinder FX-12S

FX is Hart Man Shanghai's brand "Fuxincheng" means Fuxin

12 means that the outer diameter of the grinding wheel that can be installed is 12 inches. 1 inch = 25.4MM and the outer diameter is 305MM. Among the centerless grinders, manufacturers call it type 12 centerless. Grinding machines, and similarly type 18 and type 20 centerless grinders, are the most commonly used. Some also add NC, semi-automatic, CNC, and CNC s for servo motors. Some letters represent the operating mode, and some letters represent the internal structure. Some represent its characteristics, some represent its processing range, and the brand

FX-18CNC-7Axis This is an 18-type CNC 7-axis linkage centerless grinder, which is "Dongguan Hartmann Hardware Technology Co., Ltd. ”Production