It will be clearly seen that the bolt-like piece (1) described in the space frame connection system is embossed on the shaft with the part with thread being excluded, and the groove-set is formed, and as a result of title assembly of these two parts with groove-set formed in the hole section inside the wide nut-like piece (3) within the tolerances and at the same pitch (FIG. 4/2, FIG. 4/3), the system has the strength against the serious values of excessive pressures.