The "X-Chart" Abrasion Resistance Vs. Bending Fatigue Resistance While there is a possibility, there is little likelihood that an application can be found for which there is a precisely suitable wire rope - one that can satisfy every indicated requirement. As with all engineering design problems, feasible solutions demand compromise to some degree. At times, it becomes necessary to settle for less than optimum resistance to abrasion in order to obtain maximum flexibility; the latter being a more important requirement for the given job. A typical example of this kind of trade- off would be in selecting a highly flexible rope on an overhead crane. Conversely, in a haulage installation, a rope with greater resistance to abrasion would be chosen despite the fact that such ropes are markedly less flexible. Two compelling factors that govern most decisions as to the selection of a wire rope are abrasion resistance and resistance to bending fatigue. Striking a proper balance with respect to these two important characteristics demands judgment of a very high order. A graphic presentation of just such comparison of qualities between the most widely used rope constructions and others is given by means of an X-chart. Referring to this chart when selecting a rope, the midpoint (at the X) comes closest to an even balance between abrasion resistance and resistance to bending fatigue. Reading up or down along either leg of the X, the inverse relationship becomes more apparent as one quality increases and the other decreases.