A tiller tine is the part of the tiller that digs into the soil. Tillers are used to cultivate soil and to break ground open to prepare it for planting. The rotating tines cut into the dirt and turn it over, breaking up clumps and tearing out grass and weeds. Small mini tillers usually have two to four sets of tines, while larger types of tillers can have up to eight sets.
Each tiller tine is a set of four L-shaped blades. The tines are arranged in pairs, and the blades are sharpened to allow them to cut into the soil. The blades point in opposite directions, alternating inward-pointing blades with outward-facing ones. When the blades rotate, the outward-facing blades slash into the soil and break it open. The inward-facing blades undercut across the slashes and break the soil into small pieces. As the tines turn, the blades also knock accumulated material off each other which keeps them from getting jammed.
The tiller tines pull the machine forward as they work. Mini-tillers and garden cultivators are propelled only by the motion of the tines. These can be hard work for the user, who must push down on the tiller to keep the digging depth consistent and prevent the machine from moving forward too quickly. Large tillers are generally easier to use because they have a set of wheels that operate independently of the tines. The wheels drive the machine forward and maintain a consistent digging depth.
Depending on the size of the machine, a tiller tine can dig anywhere from 4 to 12 inches (10.1 to 20.3 cm) into the soil. Mini-tillers work well in small home gardens because their cutting swath is usually only around 10 inches (25.4 cm) wide. These tillers are best used for re-opening prepared soil in the spring, weeding, and mixing in fertilizer and other soil amendments. Large tillers can cut swathes between 14 and 21 inches wide (35.5 and 53.3 cm), and are better for large gardens and hard or rocky soil.
Although tillers are useful work-saving devices, they can damage the soil if used too often or unnecessarily. A tiller tine can easily cut up an earthworm, and the violent cutting of the blades disturbs the balance of microbiotic life in the soil that keeps it healthy. Boots and protective goggles should be worn while using a tiller to protect the legs and eyes from flying debris.