This left-side tooth is the wear component that engages the soil on the left side of a rotary harrow. It is bolted to the rotor flange and is the primary cutting and mixing element; the tooth's leading face breaks clods while its trailing face throws soil rearward toward the following tine row. A worn or broken tooth reduces soil pulverization and increases the power draw on the gearbox because the remaining teeth must carry an uneven load. The manufacturer machines the mounting hole and the tooth profile to match the original rotor's bolt pattern and working angle, so no shimming or re-drilling is required during replacement. When installing, clean the mounting face on the rotor and torque the retaining bolt to the specification for the assembly.