Three-Point Hitch Category (Hitch Category)
The ISO 730 classification of the tractor hitch connection according to pin diameter and lower link spacing. The lower link pin diameter is 17 mm in Cat.0, 22.4 mm in Cat.1, 28.7 mm in Cat.2 and 37.4 mm in Cat.3; the spacing between lower link pins is approximately 500, 718, 870 and 1010 mm respectively.
The category determines whether the implement will mechanically fit the tractor. If pin diameter and spacing do not match, the implement either cannot be attached or requires adapter bushings/forks. Category selection roughly follows the tractor's power class: Cat.0–1 on small garden tractors, Cat.2 in the mid class, Cat.3 common in heavy field work.
- Lower link pin diameter and the spacing between pins are the two basic dimensions that define the category.
- Top link pin diameter also varies with category; check both dimensions together when buying an implement.
- Intermediate categories (e.g. Cat.1 lower links + Cat.2 top link) can be encountered in the field.
For AXI electronic retrofit kits, category is not a selection criterion. LFT20, LFT54 and ELF-812 do not connect to the hitch links, the pins or the lift cylinder; they are fitted on the control side, that is, to the cable or the hydraulic control lever. So whether your tractor is Cat.1 or Cat.3, the kit choice does not change. What decides is not the category but the presence of a cable-pulled quick lift mechanism on the tractor.
Context in which this term is used: Converting a tractor hydraulic lever to electronic control