A drill guide system for a bone plate having holes includes a guide block having at least two drill guide bores alignable with a bone screw receiving hole in a bone plate. A locking element extending through at least one drill guide block bore into the bone plate bone screw receiving hole, the locking element having a partially threaded bore portion and having a bifurcated tip surrounding the threaded bore portion. The bifurcated tip capable of engaging an inwardly extending protrusion formed on an internal wall of a bone screw receiving hole in the bone plate. An axially moveable threaded rod has a head for contacting an outer surface of the guide block and an end portion engaging a portion of the bore in the bifurcated tip of the locking element for separating sections of the bifurcated tip on axial movement of the rod prior to the head contacting the second surface of the drill guide block.