What is the German name for this tool?
It is used to divide lengths into equal sections. In English it is called an equal spacing divider. It is used in engineering.
It is called a Streckenteiler.
The best I found was a german Amazon page:
Diese 12 \"10-Punkte-Teiler auch als ein 11-Punkte-Teiler aus Edelstahl aufgebaut sind.
So they call it 11-Punkte-Teiler, but the product description is written in poor German though I may be wrong.
Btw. If you want a german name to an image, just use the German Google site. Go to Images » Search by image and paste your image URL