According to Eurocode 8 moderate to high dissipative behaviour of timber structures requires sufficient ductility of the critical regions. Earlier experiments on timber connections with slotted-in steel plates and laterally loaded common steel dowels rarely achieved high ductility values. Connections consisting of LVL-C members, dowel-type fasteners with different post-elastic steel properties, full confinement of the timber member and measures to restrain the notch effect were investigated by means of monotonic and cyclic tests with regards to the displacement ductility. The measures taken proved to be effective in enhancing the plastic deformation capacity of the steel dowels to a large extent. However, a new aspect was observed: the constriction of the dowels in the contact area with the plate. The research results provided a better understanding of the factors influencing the behaviour of slotted-in steel plate connection.