German to English Tech/Engineering Construction / Civil Engineering geometry

This term is used in a patent application for structural ceiling panels. My architectural dico translates "Normale" as normal, perpendicular, perpendicular line, master. The idea is the dowels run horizontally through a sandwich of boards, perpendicular to the face sides of the boards. Does "surface perpendiculars" exist? Is it a good translation of Oberflächennormale?

Plattenelement dadurch gekennzeichnet, dass in Längsrichtung der Bretter gesehen abwechselnd in die beiden Neigungsrichtungen gegenüber der Oberflächennormalen geneigte Holzdübel vorgesehen sind.

Panel element characterized by the fact that from the perspective of the longitudinal direction of the boards, wooden dowels are provided that run alternately in both angled directions with respect to the surface perpendiculars.