This series of tools is used to produce internal squares.
Each insert can make squares or hexagons of different sizes (e.g. insert IN-SQ-27/37 can make squares from 27 to 37mm A/F).
The size of the bore must have a diameter 5% bigger than the size of the square.
INSERTS FOR INTERNAL HEXAGONAL PROFILES
The size of the bore must have a diameter 2% bigger than the size of the hexagon.