CNC bits 1.tungsten ,superhard alloy 2.dia:3.175mm ,6mm 3.can engraving the pcb wood,plastic, arcylic cnc router bitsMaterial:tungsten steelApplications:ABS,PVC,ACRYLIC,PLASTICcnc router bitsFLAT BOTTOM ENGRAVING BITSengraving bitsFLAT BOTTOM ENGRAVING BITS cnc bits