This second edition cancels and replaces the first edition (1975). Gives the specifications and dimensions for the assembly and clearances common to hydraulically operated cylinders and to trailing-type farm implements. The specifications given permit: the interchangeability of hydraulic operation between tractors, and the transference of the hydraulic cylinder from one implement to another. It applies to three categories of tractors as follows: 1 (up to 35 kW), 2 (30 to 75 kW), 3 (over 70 kW).