The term "factory belt" typically refers to a region where there is a concentration of factories or manufacturing plants. However, there are other terms that can be used to describe such areas. One term that is often used is "industrial zone," which refers to an area that is designated for industrial activity. Another term is "manufacturing district," which is similar to an industrial zone but may also refer to a specific area within a city or town. Additionally, the term "production hub" can be used to describe a region that is known for its manufacturing capabilities. Other synonyms may include "manufacturing belt," "industrial corridor," and "factory district".