lõikeriista kulumine, mis avaldub kulumisriba moodustumisena tagatahul ja mida hinnatakse kulumisriba laiusega (vt tagatahk; vrd kulumine esitahul), the loss of relief on the flank of the tool behind the cutting edge due to rubbing contact between the work and tool during cutting; measured in terms of liear dimension behind the original cutting edge (see: flank; compare: crater wear)