shredder with inserts

this is version of my shred 5 sq but i have made the cutters so that they accommodate metal cutter inserts. this should be able to cut harder material then.
the inserts could be made from rectangular metal of some kind but you may want to grind the edge to be more angles as in the shown with the modeled inserts.
you can thread the holes for 6-32 screws because the holes are the right size for that.
an exploding animation showing insert and cutter relationsip is her : https://youtu.be/QEZa5IPZ8Rk