A joint device of an agricultural machine has at least one tool-bearing beam (2a-c, 3a-c) for soil tillage tools (4, 5, 38, 39), such as seed coulters and cultivator tines, whereby a portion (10) of the beam end, at least on one side of the machine, is detachably fastened by means of a bolt/nut connection (13, 18, 23) arranged within the tool-bearing beam. A threaded body (18, 50) in the bolt/nut connection is fixed, preferably plug welded, in the main part of the beam (2a-c, 3a-c).