Abstract: For mulch tillage burrying the residue is very important. Especially recently heavy-duty disk harrow is often used for breaking the soil and incorporating the residue into the soil. In this study, the performance of the heavy-duty offset disk harrow in a soil bin was examined. The objective of this study was to investigate the effect of forward speed, angle and weight of the disk harrow on draft and soil conditions in the soil bin. Heavy-duty disk harrow with 11 disks (reduced to the half size) was operated in a soil bin without stubble to see the effect of the tillage parameters alone on the soil conditions. The disk harrow was operated at speeds of 5.2, 7.9 and 9.8 km h-1. The angles of the disk harrow were 10, 14 and 22°. The weight, speed and the angle of the disk harrow were found statistically significant for draft. Also the interactions of three factors were significant. The increasing angle, weight and speed increased the draft. Especially increasing the angle of the disk harrow dramatically increases the draft. The bulk density of the soil was only affected from the angle of the disk harrow. The weight and the speed did not have any effect on bulk density of the soil. Soil size changed with only changing the angle; increasing the angle increased the clod size.