Hole Template

thingiverse

This is a set of hole templates ranging from 12mm to 26mm (in 1mm increments) on the bigger one and 3mm to 11.5mm (in 0.5mm increments) on the smaller one. The holes may not be 100% accurate to the size due to the way you draw inside them with your pencil (mechanical pencil or at least 2H works best). So maybe do a test of one before you draw it on your nice neat technical drawing. The bigger ones are more accurate. With the smaller ones I normally use the hole 2 sizes up from what I want.