The process of tillagetool wearis the most important factorthat limitingtheuseful lifeand efficiencyof thesetools. This study aimed to investigatethe effects ofdepth and functioning level onchiselplowblade wear andidentify itscritical point. Experiments were conducted inclaysiltsoilsin12hectares. The depth and functional level was tested in 3 and 5 different levels, respectively. The resultsshowed thatdepth and functional level variables andtheir interactionhavea significant effectonthebladeedge andtipwear(P = 0.01). Mean comparisonshowed thatthe most wearrateis related toA1d3 (functioning level =12 hectaresanddepth= 25 cm). The results alsoshowed that thetip of thebladeisworn quicklyonthe firstworking day. The results showed that0.57% weight loss ofthe blade wasinthe first working dayand 0.42 %wears in thetenthhectares. Theresultsshowed that on thefourthday, plowoperationrate was 22 %less thanthe first day, and subsequently, thetractorfuel consumptionwas28%higher thanthe first dayof work.