A professional who tends machine that stones and polishes bevel face (outside periphery) of screwheads. Respnsibilities include:

• Inserts screws in spring chuck.
• Swings stoning face into position against rotating heads and holds it in place until pilot bulb lights, indicating heads are stoned to size.
• Turns stoning face away and swings polishing lap into position against rotating heads to impart finish to bevel faces.
• Removes finished screws from chucks.