Abstract: A tool for cutting divisible strips of frangible material having pre-break lines disposed at predetermined spacings comprises an elongate channel support within which a slider captively slides. The support is adapted to receive a divisible strip therein through an open end thereof. The slider has a surface define a stop against which the strip will strike. The support has along its side walls, a series of markings arranged at predetermined pitches corresponding to whole numbers of unit spacings of the break lines between the stop on the slider and the open end face of the support. The support further includes locking means that resilient lock the slider at the positions of the markings such that by sliding the slider to one of the selected markings variously sized strips can be obtained by breaking the strips by a lateral pressure applied thereto against the end face of the support.