It is acceptable practice to use more than one type of thread representation on a drawing.

It is indeed acceptable to use different types of thread representation on a drawing, depending on the specific requirements or characteristics of each element being represented. Different thread types may include basic threads, pipe threads, fine threads, coarse threads, and others. However, it is important to ensure consistency and clarity within the drawing, and to provide appropriate keynotes and symbols to help users interpret the different types of threads used.