Side-action injection molding uses mechanical or hydraulic slides to release undercuts, and, as the name suggests, the slides move in a horizontal or lateral direction perpendicular to the mold opening and closing. On the other hand, horn pin injection molding, also known as cam pin or angle pin molding, uses an angled pin system to drive the slide movement. The opening of the press causes the slide motion in horn pin injection molding, and the angled pin withdrawing from the angled hole moves the slide back to release the undercut.