You just measure the gap between the tractor male output spline and the machine (implement) input spline (when you have the machine fitted onto the tractor links)
Give us the measuremeant and we will do the sizing in our workshops.
You get the right size shaft delivered overnight or by 72hr courier (cheaper)
Details needed when you order are:-
1/ tel us the make and hp of the tractor shaft its being fitted to......
2/ tel us the model/type of implement being fitted......
3/ tell us if you want the shaft sizing or just off the shelf......
4/tell us if you want us to size your shaft for you (in which case please give the measurement) or if you want an off the shelf shaft to size yourself.
5/ add any extras you want eg....New machine guards...New safety chains etc for either tractor or implement....