To many casual users, tractor 3 point linkage pin sizes are a mystery.T he three-point hitch is a standardized method of attaching implements (equipment) to tractors.
Below, I have listed what sizes of pins are used on different sizes of tractor:
Category 0 Usually found on subcompact tractors/ ride on mowers
16mm - 5/8" Diameter pin both top and bottom.
Category 1 Usually found on tractors from 16 - 45HP
19mm - 3/4" Top Link,
22mm - 7/8" Lower linkage
Category 2 Usually found on tractors 45 - 120HP
25mm - 1" Top link
28mm -1-1/8" Lower linkage
Category 3 Usually found on tractors 100HP-225HP
32mm - 1-1/4" Top Link
38mm- 1-7/16" Lower Linkage