Shredder heads should have durability and a shredding tier just like picks, drills and jackhammers but with one key difference: better materials mean more things to shred and longer shredder lifespans. When the heads inside the shredder break, the machine just stops processing until new heads are installed.
When the shredder heads break, the machine outputs some scrap metal and gem dust, depending on the shredder heads’ construction. The scrap metal inside the machine has to be removed from the mechanism as the little shards and abrasive dust can interfere with lubrication. (a seized up shredder is no good!)
Gem-augmented shredder heads are made by adding gen dust to metal shredder heads, with the brick/gem dust as an abrasive. The abrasive brick/gem dust improves its grinding power when used on metals. (useful for recycling your spare machines!)