The linkage and accessory product described in this web site are components of the typical three-point hitch system that
is standard on most all farm tractors today. The basic function of the system is the attachment and adjustment of agricultural
implements. The three primary parts of the system are the top link and two lower lift arms as shown in illustration below.
Adjustment of one or all of these components allows the tractor operator to raise, lower or tilt an implement. The three-point
linkage parts described on this web site are built to standard specifications set by the American Society of Agricultural
Engineers (ASAE).
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Click to launch an interactive presentation of the Three Point Hitch System.
Categories 0, 1, 2, 3 & 4 are used to classify tractors by drawbar power. The below table gives dimensions and horsepower ratings associated with these categories.
| Maximum Drawbar Horsepower | Top Link Pin Diameter | Draw Pin Diameter | Lift Arm Spacing |
| Cat. 0 - up to 20 | 5/8" | 5/8" | 20" |
| Cat 1- up to 45 | 3/4" | 7/8" | 26" |
| Cat 2- 40 to 100 | 1" | 1 1/8" | 32" |
| Cat 3- 80 to 225 | 1-1/4" | 1-7/16" | 38" |
| Cat 4- 180 to 400 | 1 3/4" | 2" | 46 " |