1-1/8" Wire Rope (Iwrc) - 6X37 CLASSIFICATION Because of emphasis on fatigue resistance the problem of choice within the 6x37 Classification is greatly reduced. Although there are exceptions, the constructions in the 6x37 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. In sizes over two inches, the 6x49 SWS construction is normally used. In smaller sizes, however, the outer wires in the 6x49 SWS would be so small that their resistance to abrasion would be lowered. It should be noted that the greater number of wires make the 6x37 classification more susceptible to crushing. This, however, can frequently be overcome by an independent wire rope core and by the use of well designed sheaves and grooved drums. Order 1-1/8" 6x37 Iwrc wire rope in bulk today.