The load requirements are covered by sizes further divided into 15 load groups.

Within one load group (nominal load), all components show unified load limits and safety margins. The connection geometry of the components (thread and pin diameter) are unified within one load group and are therefore compatible. For this reason, components from different product groupsunified load group can be connected together as safe load chains. By this way the faulty arrangement of differing load groups is excluded. and within only one