Make tools, fittings, and small metal pieces used in other products.
Operates pebble mill to grind emery, rouge, and other abrasives and separates them according to fineness by water suspension method: Examines abrasive under microscope to determine grinding time required, and grinds abrasive in pebble mill. Turns valve to allow ground particles and water to flow into agitator tank. Presses button to start agitator which stirs particles into suspension. Stops machine and determines by microscopic examination when particles of particular grade have settled below tank outlet. Opens stopcock to allow particles remaining above the outlet to descend into vat. Repeats separation process for other grades, regrinding as required.