The said industrial design consists of the shape, configuration, ornamentation and pattern the mechanical pencil shown in the drawings; the mechanical pencil has a generally cylindrical tubular left portion and an axially aligned tubular right portion; the axially aligned tubular right portion has three generally cylindrical and identical outer surface portions with three equally spaced-apart generally identical axially aligned depressions extending almost the length of the tubular right portion alternately situated between the generally cylindrical and identical outer surface portions; each depression has a smooth curved bottom surface; a clip portion having a flat outer surface is situated above one of the generally cylindrical outer surface portions and extends from a curved shoulder portion adjacent the right end of the tubular right portion part way along the length of the tubular right portion to a curved end in plan view which bends slightly away from the adjacent generally cylindrical outer surface portion of the tubular right portion; the right end of the tubular right portion merges into a smaller axially aligned right end section having an outer surface which conforms to the surface of the tubular right portion but is somewhat smaller in diameter; the left end area of the tubular left portion has a pattern of generally parallel spaced-apart wavy lines extending around the left end area; the left end of the tubular left portion has a beveled outer end surface. In a first projected position of the mechanical pencil, a writing unit projects outwards away from the beveled outer end surface of the tubular left portion and the small axially aligned right end section of the tubular right portion is shortened in length.In a second projected position of the mechanical pencil, a tubular generally cylindrical portion projects outwards away from the beveled outer end surface of the tubular left portion and the smaller axially aligned right end section of the tubular right portion is shortened in length.Representations of the design are shown in the figures wherein:Fig. 1 is a perspective view of the design of the mechanical pencil with the eraser and the writing unit in a retracted position;Fig. 2 is a front view thereof;Fig. 3 is a bottom view thereof;Fig. 4 is a left side view thereof;Fig. 5 is a right side view thereof;Fig. 6 is a rear view thereof;Fig. 7 is a front view thereof with a writing unit projected from the left end of the tubular casing of the mechanical pencil;Fig. 8 is a front view thereof with an eraser projected from the left end of a tubular casing of the mechanical pencil; andFig. 9 is a sectional view thereof along A-A of Fig. 2.Diagrams of the design are included.