6 x 19 and 6 x 37 classification ropes provide an excellent balance between fatigue and wear resistance. They give excellent service with sheaves and drums of moderate size.
6 x 37 classification because of the emphasis on fatigue resistance the problem of choice is greatly reduced. Although there are exceptions, the constructions in the 6 x 37 classification are primarily designed to be the most efficient for each rope diameter. As the rope size increases, for instance, a large number of wires can be used to achieve required fatigue resistance and still those wires will be large enough to offer adequate resistance to abrasion. It should be noted that the greater the number of wires make the 6 x 37 classification more susceptible to crushing. However, this can frequently be overcome by an independent wire rope core (IWRC) and by the use of well designed sheaves and grooved drums. 6 x 19 classification has outer wires larger than 6 x 37 classification, and therefore its resistance to abrasion is increased, but its fatigue resistance is decreased. 6 x 19 classification is a good rope to withstand abrasion or crushing on the drum.