Power consumption decrease is an important factor at the soil tillage and for the choice of working tools, in particular disc ones which are mounted on plow, harrow, disc headers, and stubblers. The authors have assumed that transformation of the external blade edge of a segment of a cutout disc towards his concave surface will reduce power consumption of interaction. A laboratory setup was used for mounting V-shaped and chisel-tipe tines, plow bodies, disc working tools. A lead angle and tillage depth can be changet due to basic wheels. Segments of three 560 mm cutout disks were plastic deformed. The external bladeg edge of a segment was unbent by means of a templet and controlled by the measuring tool. Test conditions: a background is a cereal crops stubble, soil type is clay loam, absolute humidity equals 24.47 percent, hardness is 2.44 MPas. The horizontal component of traction resistance of cutout discs with the blade edge transformed by 1, 2 and 3 degrees external is less than similar parameter of standard working tool on 24.86; 30.92 and 27.48 percent respectively. At the same time degree of plant remains incorporation accrued by 2.63; 5.96 and 8.30 percent in absolute terms. The soil surface crumbling coefficient increased by 2.27; 4.51 and 20.33 percent in absolute terms. The size of a surface roughness decreased by 12.75; 33.33 and 41.44 percent respectively.