Three-point hitches are the mechanism used to mount implements to farm tractors. There are four categories: 0, 1, 2 and 3. The configuration of the three-point hitch includes a single center-mounted attachment point at the top of the assembly and two mounting points mounted at a lower level. The hydraulic system of the tractor is used to raise and lower the top mounting point to effectively raise or lower the attached farm implement.
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Each category of three-point hitch is designed for a specific range of tractor horsepower, according to the website Antique Tractors. Category 0, or category 1 if a 1-to-4 numbering system is used, is used on tractors of less than 20 horsepower. Category 1 is standard on tractors of 20-to-45 horsepower. Category 2 is used on tractors up to about 90 horsepower, and category 3 is generally used on tractors over 90 horsepower. Tractors with a horsepower on the border between categories can have either hitch depending on the manufacturer's design.
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Each progressive category of three-point hitch has heavier brackets and accommodates heavier iron pins in the mounting hardware of the implement. Category 0 three-point hitches accept only 5/8-inch pins, while the category 3 hitch accommodates a 1 1/4 -inch pin in the top fitting and 1 7/16-inch pins on the lower fittings of the three-point hitch.
Tractors and Implements
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Know the horsepower requirement of the farm implement before attaching it to the three-point hitch. According to the website Union Farm Equipment, if the tractor has enough power to pull the farm implement, the three-point hitch of the tractor can lift and control the implement. The bottom two arms are used to adjust the height of the implement and the top arm is used to adjust the pitch of the implement and, if necessary, lift it from the ground. One of the advantages of the three-point hitch system is its universal use. The system has seen few changes since its introduction in 1939.