Millwheel or
water wheel are sometimes used as a charge in
heraldic arms. The water wheel is often used to symbolize the food processing industry or industry in general.
The heraldric millwheel is usually stylized and may look different in the
heraldic traditions of different countries.
Examples
Mühldorf am Inn (canting, since the name means "Mill village on the Inn")
The arms of
Bonsmoulins, France, with a millwheel in the base
The arms of
La Courneuve, France, with a millwheel in the door opening