Abstract: A heat exchanger tube plate is provided having tubular pieces for protecting its face or the ends of its tubes, of the type each comprising a cylindrical sleeve with bent back circular edge, or head, forming a collar and positioned inside the end of said tubes or bores. According to the invention, the head of said protecting pieces has for external contour a polygon whose sides, parallel in pairs, are perpendicular to the planes joining the axes of the tube, or bore, of the tube plate to which they are applied to the axes of the adjacent tubes or bores, the distance between the parallel sides being greater than that separating the adjacent axes situated in the plane to which the sides are perpendicular, and one of the sides having an offset flange, namely a flange offset with respect to the plane of the head by a height substantially equal to the thickness of this head.