Components with external threads (e.g. stand rods or bolts) and components with internal threads (e.g. stand plates or nuts) need to match. Standards help to ensure that, despite a separate production, the function of components of the same nominal sizes is always guaranteed.
Unit of measurement:
Thread sizes are indicated by using the letter M in the product data. The metric ISO thread is a globally standardized thread that has been improved over the previous metric thread, but is interchangeable with it in most cases. (DIN 13) (Metric System).
Examples at Bochem products: M6, M8, M10.