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GENERAL
INFORMATION ON WIRE ROPE
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The
three basic components of a typical wire rope. (Fiber core is
shown.)
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COMPONENTS:
Wire
rope consists of three basic components.
1.
Wires.
2.
Strands, formed by wires, laid helically around a core.
3.
Core, or center.
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MATERIAL:
Steel
grades in wide use today are IPS (improved plow steel), EIPS
(extra improved plow steel), sometimes also referred to as
XIPS, XIP, or EIP, as well as EEIPS (extra, extra improved
plow steel).
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CORE:
Its
function is to provide proper support for the strands under
normal conditions. Three types of core (or center) are
commonly used.
1.
Fiber Core (F.C.), usually polypropylene (P.C.), sometimes
hemp (H.C.) and sisal.
2.
Independent Wire Rope Core (IWRC)
3.
Wire Strand Core (WSC)
IWRC
and WSC are sometimes referred to as steel wire core or steel
center.
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CONSTRUCTION:
Expressed
in numbers of strands x number of wires. 6 x 25 indicates that
the wire rope consists of 6 strands, which in turn have 25
individual wires. Constructions are grouped into classes:
6
x 7 Class: Containing 6 strands that are made up of 3 through
14 wires, of which no more than 9 are outside wires.
6 x 19 Class: Containing 6 strands that are made up of 15
through 26 wires, of which no more than 12 are outside wires.
6 x 36 Class: Containing 6 strands that are made up of 27
through 49 wires, of which no more than 18 are outside wires.
8 x 19 Class: Containing 8 strands that are made up of 15
through 26 wires, of which no more than 12 are outside wires.
19 x 7 Class: Containing 19 strands, each of which is made up
of 7 wires.
8 x 19 and 19 x 7 class wire ropes have rotation-resistant
properties, excluding elevator ropes.
The
constructions listed above are just some of the more popular
constructions.
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| Other
common constructions:
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7
x 7, 7 x 19: |
Galvanized
cable. Sometimes referred to as "aircraft cable" but not
intended for aircraft use. |
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x 7, 1 x 19: |
Strand |
7
x 7 x 7, 7 x 7 x 19: Cable Laid
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Many
others exist, some for highly specialized applications only.
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Note
that any class denotes the nominal
number
of wires in each strand. The actual
number
of wires may be different. For example 6 x 36 class: strands
most commonly consist of 36 wires, or 31, or 41.
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