Page 4 of Rigging by Vanguard Steel

wire ropes measuring wire rope the diameter of a wire rope is the diameter of the circle which encloses all the wires when measuring wire rope it is important to take the greatest distance of the outer limits of the `crowns of two opposite strands a measurement across the valleys will result in incorrect lower readings correct incorrect rope constructions small diameter cables ranging in diameters up to 3/8 the construction material and finish of these cables depends on their ultimate use 1 commercial quality cables often referred to as aircraft cables but not for use in aircraft 2 control cables used in the automotive industry 3 conveyor belt cables engineering general purpose wire ropes the construction of wire ropes and strands covered under this heading varies within specific classifications and will depend on the desired performance features such as flexibility resistance to abrasion resistance to rotation etc 1 x 7 classification guy strand 6 x 7 classification used where ropes are dragged over the ground or over rollers and where resistance to abrasion is an important factor the large outer wires will withstand a great deal of wear at the expense of flexibility 6 x 19 classification constructions falling under this classification are the most widely used throughout all industries as they feature a good balance between abrasion resistance and flexibility 6 x 37 classification increasing the number of wires while reducing the wire diameter results in greater flexibility but diminishes abrasion resistance 19 x 7 classification due to their rotation resistance characteristics ropes falling under this classification are being used for many hoisting applications but failure to easily detect damage to the inner core is among the reasons that usage has declined in favour of specialty ropes 8 x 19 classification reverse bends and small sheaves may render 8 strand ropes a better choice than 19 x 7 or other rope constructions specialty ropes for applications where performance down-time and/or safety considerations outweigh a rope s cost of acquisition a wide range of specialty ropes has been developed proper selection handling and installation of such ropes is essential in maximizing results vanguard steel ltd.

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