What are the oil mill and sand belt tools in the furniture factory for?

General furniture practices are carpentry, painting, priming, finishing and packaging. Oil grinder is an oil grinder who manually polishes (polishes) furniture panels after spraying primer; The grey belt sander has a big machine called belt sander. Put the flat plate, the abrasive belt rotates on it, and the machine is controlled manually. That kind of machine is called a gray belt sander.