Universal earthing clamp in accordance with DIN EN 62561-1 for integrating mounting systems, e.g. of PV systems, into functional equipotential bonding/functional earthing (conductor colour black, if applicable) and lightning protection equipotential bonding installations in accordance with DIN EN 62305-3 (VDE 0185-305-3). The contact plate (intermediate element) made of stainless steel allows different conductor materials (copper, aluminium, hot-dip galvanised steel and stainless steel) to be connected to the usual mounting systems, e.g. made of aluminium, without contact corrosion. Version with M8x30 mm hammer-head bolt, self-locking nut and double cleat, e.g. for through-wiring of profiles.