Centering Square

Centering square with a side length of 10cm. I milled the square from 15mm birch plywood, with the milled-out area being 10mm deep. I mainly use the square for finding the center point of smaller wood discs and dowels. The version in the photos was milled entirely with a 4mm end mill. I recommend using a smaller bit for milling the marking line, around 1.5-3mm. But that of course depends a lot on which marking tools or pens you use.