A professional who tends grinding mill that crushes powder or explosives ingredients, such as sulfur, saltpeter, and charcoal, used in manufacturing gunpowder. Respnsibilities include:

• Charges mill with prescribed amounts of ingredients.
• Starts mill wheel revolving for specified time or until materials are crushed and mixed and rakes or dumps contents into containers for storage or further processing.
• When tending mill that crushes finished powder to grains of specified size to attain uniform ballistic properties, is designated Graining Operator.
• May tend vibrating screens to separate particles of varying sizes.