An access door has a rectangular outer frame adapted to be set in a wall and having two longitudinal sides and two transverse sides defining four corners and a rectangular inner frame dimensioned to fit within the outer frame. Respective hinge plates fixed at corners at ends of one of the longitudinal sides of the inner frame each have an outer part bearing outward on a back face of the outer frame for holding the inner frame in the outer frame and for pivoting of the inner frame in the outer frame generally about the one longitudinal side. Each of the plates is formed with a transversely outwardly open centering notch. Respective centering tabs on the outer frame are engageable in the centering notches of the hinges.