Abstract: A disjoinable assembly designed for connecting of piston with piston rod in ngines and machines, this assembly being particularly suitable for use in compressors, includes an insert [4] and a bolt connector [3] mounted in the said insert, said connector co-operating with piston rod [2]. The insert [4] is U-shaped in cross-section, it has preferably the form of a cylinder with bottom [8] at one end, said bottom having a hole [9], and it is provided with bearing surfaces [12] in the form of splineways [10] or splines [14] , said bearing surfaces [12] being matched with bearing surfaces [13] made in the form of splines [11] or splineways [15] on the piston rod [2] . The insert [4] is fixed in position relative to piston [1] and piston rod [2] by means of dogs [20] , said dogs being formed by bending the sections of rim [16] toward one or more sockets [6] made in piston [1] , and by bending the other sections of the said rim [16] toward one or more sockets [17] made in connector [3].