Kiswire - Steel wire rope

GENERAL INFOMATION ON WIRE ROPE
for SELECTION & USAGE
1.DIAMETER
The diameter of rope is the diameter of its circumference, circumscribed to its normal section. This diameter is given in
millimeters.
1) PRACTICAL DIAMETER OF WIRE ROPE
The practical diameter of a rope is measured by following an established method, its value must be equal to the value
of the nominal diameter (the dimension by which a rope is identified) except for certain allowed tolerances.
2) HOW TO DETERMINE THE PRACTICAL DIAMETER
Measurements are taken at two points at least one meter apart and two diameters are measured at 90° one from the
other. The average of the four values thus obtained is the practical diameter. Usually the practical diameter is taken
from a sample of straight rope not subjected to traction. In special cases when the tolerance is less than 5% of the
minimum guaranteed breaking strength.
The correct diameter is the greatest diameter of the rope or strand.
correct
wrong
2. CONSTRUCTION AND DESIGNATION
The strand is the simplest construction: it consists of one or more layers of superimposed wires laid spirally around one
or more central wires or around a fibre core. The construction of the strand is identified by the number of wires in the
individual layers, starting from the outer one(e.g. 12+6+1 or 15+9+FC).
FC indicates a fibre core. Distinction is made between strands with cross laid and equal laid wires.
1) STRANDS WITH CROSS LAID WIRES
All the wires in this type of strand are of equal diameter and for geometrical reasons the number of wires decreases in
each layer, starting from the outermost one, according to an arithmetical progression based on number (18 + 12 + 6 + 1
or 12 + 6). In cross laid constructions each layer of wire is laid up a separate operation with a different length of lay,
the result being the crossing of the various layers of wires. Consequently strong pressure occurs between the wires
which may break, especially with variable loads.
2) STRANDS WITH EQUAL LAID WIRES
In these constructions the pitches of the various layers of wires are identical as stranding is carried out in a single
operation; therefore, the contacts between wires are lindar. Seale, Warrington and Filler strands belong to this
construction. Wires of different diameters are required for these constructions.
As for example:
Seale : 9 + 9 + 1
Warrington : 6/6 + 6 + 1
Filler : 12 + 6F + 6 + 1
Steel Wire Rope | 05