A professional who tends battery of automatic squaring machines that mill (file) flat round sides of engaging portions of winding stems and barrel arbors. Respnsibilities include:

• Loads sleevelike feeding magazines with stems or barrels, using tweezers.
• Inserts magazine in machine and starts machine.
• Inspects parts, using loupe, to see that square is centered on stem (sides are milled flat leaving rounded corners).
• Gauges squares in go-not-go gauge.