Brush hog

A brush hog or "bush hog" is a type of rotary mower. Typically these mowers attach to the back of a farm tractor using the three-point hitch and are driven via the Power take-off (PTO). It has blades that are not rigidly attached to the drive like a lawnmower blade, but are on hinges so if the blade hits a rock or stump, it bounces backward and inward, and then centrifugal force makes it go outwards again.

The rotary blades are not sharpened in the same way as a conventional mower blade. They are usually quite dull so they whack through dense plant growth, whereas a sharp blade often gets stuck or slowed down. The blades are very heavy, up to an inch thick, so the centrifugal force pulling out is stronger than the forces of the vegetation bouncing in. They are made of heat treated high carbon steel that can withstand strikes with hard objects such as rocks and stones.

The archetype of this type of mower is the Bush Hog which is made by Bush Hog, Inc. Selma, Alabama. The formal name for this type of implement is a rotary cutter or rotary mower, although it differs from mowers in that it does not cut with a sharp blade, but rather severs with an intentionally very dull wedge-like blade.

Several other manufacturers make these types of mowers including:

There are two types of attachment for a rotary mower, either using the three-point hitch or via a draw bar. The height of the cut on models attached on the three-point hitch is adjusted using the hitch control lever. This adjusts the height of the front of mower. For more radical height adjustment the rear wheel can also be adjusted. Typically the mowers in this category range from 3.3 to 22 feet (1 to 7 m) mowing widths.

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