6 x 19 Class
Wire Rope
The 6 x 19 classification of wire ropes
includes standard 6 strand, round strand ropes with
16 through 26 wires per strand. The 6 x 36 classification
of wire ropes includes standard 6 strand, round strand
ropes with 27 through 49 wires per strand. Although
their operating characteristics vary, all have the
same weight per foot and the same minimum breaking
force, size for size.
While the 6 x 19 ropes give primary
emphasis to abrasion resistance in varying degrees,
the 6 x 36 ropes are important for their fatigue
resistance. This fatigue resistance is made possible
by the greater number of small wires per strand.
Although there are exceptions for special
applications, the constructions in 6 x 36 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.
6x19 classification
ropes
6x19S (Seale) In this construction,
each strand has nine outer wires over nine smaller
inner wires over one large center wire. A comparison
of cross-sections shows that these outside wires
are larger than those of the 6 x 25FW or 6 x 26WS.
Therefore, its resistance to abrasion is increased,
but its fatigue resistance is decreased. This is
a good rope to withstand abrasion or crushing on
the drum.
6x25FW (Filler Wire) To most wire rope
users, 6 x 19 means 6 x 25 filler wire. It was the
most common rope in the 6 x 19 classification. This
rope has a good balance between both abrasion resistance
and fatigue resistance in relation to other ropes.
6x26WS (Warrington Seale) This construction
has better resistance to abrasion than a 6 x 25FW.
It also features a compact construction with solid
support for the wires; hence, it has a high resistance
to crushing. Its number and relative size of the
inner wires add to the stability of the strand and
gives it a fatigue resistance comparable to a 6 x
25FW.
A standard 6 x 26WS construction provides
the best rope for a wide range of applications. In
general, we recommend the use of a 6 x 26WS in any
application where a 6 x 25FW is used.
In most rope sizes, only one 6 x 36
classification rope is made. These constructions
were selected to provide fatigue resistance without
having wires that are too small.
The greater number of wires in the
6 x 36 classification makes these ropes more susceptible
to crushing. This can be minimized, however, by specifying
an Independent Wire Rope Core (IWRC) and by using
well-designed sheaves, grooved drums and proper operating
techniques.
Available galvanized at 10% lower strengths,
or in equivalent strengths on special request
Rotation Resistant Ropes
Rotation-resistant ropes can frequently
provide the best and most economical service in specific
applications when you choose, handle and use them
properly.
Contra-helically laid, rotation-resistant
ropes are different from standard ropes because they're
designed to reduce rope torque. Modes of failure
and wear for rotation-resistant ropes can differ
from those for standard rope constructions. The very
nature of these ropes requires special handling,
selection and usage not encountered with standard
constructions. They are susceptible to kinking, crushing
and unbalancing in the form of "core pops" and "birdcages".
Use extreme care to avoid operational practices that
can possibly lead to these conditions.
Rotation-resistant ropes should not
be used with swivels that allow rope rotation --
or in single part lifts where the load can rotate.
Rotation will cause a reduction in strength, unequal
loading in the rope and possible rope unbalance.
If any significant change in diameter is found in
a short length of a rotation-resistant rope, the
rope needs to be replaced.
These ropes should be replaced when
you see two randomly distributed crown wire breaks
in six rope diameters -- or four randomly distributed
crown wire breaks in 30 rope diameters.
Because rotation-resistant ropes are
special, there are separate design, maintenance,
inspection and removal criteria established for them
by applicable industry regulations and standards.
Rotation-resistant ropes should be
used with a minimum design factor of 5.0.
Flex-X
19 
Made
in America
Flex-X ® 19) delivers
extra value when you need high strength in a rotation-resistant
wire rope. Its rotation-resistant construction provides
a smooth, extremely compact wire rope with more steel
in the cross-section than conventional ropes.
Flex-X 19 is made from 19-wire Seale
strands. Six strands are laid around a core strand
in one direction, then 12 Strands are laid around
this first operation in the opposite direction. Because
of its tightly compacted, smooth design, Flex-X 19
offers advantages:
- More crush resistance than a standard 19x 7
rope while providing the same rotation resistance.
- Higher strength-to-diameter due to compacted
wires in the strands. With increased metallic
area, it provides rope strengths equal to 6 strand
XXIP IWRC ropes of the same diameter.
- Resistance to bending fatigue due to the uniformity
of the wires within each strand. The strand's
outer surface is smooth, reducing contact pressures
between the rope's strands and radial pressures
as it operates over sheaves and drums.
- Exceptional stability due to the higher density
strands coupled with the smooth outer surface.
- Improved handling, operating and spooling characteristics.
- Reduced wear to sheaves and drums.
Flex-X / Power Flex has also demonstrated
greater fatigue resistance to substantially cut rope
expense and extend rope service life. It's ideal
for single-part or multi-part hoist lines wherever
you encounter spooling problems, drum crushing, block
twisting or have fast line speeds.
19 x7 rope
In an application where a single-part
hoist rope is used to lift a free load -- or where
rotation-resistant properties are essential for rope
performance -- the 19 x 7 can be used. Its rotation-resistant
characteristic is achieved by laying six strands
around a core strand in one direction, then laying
12 strands around the first operation in the opposite
direction. Thus, when the rope is in tension, opposing
rotational forces are created between the inner and
outer layers.
In addition, frequent and regular inspection
for broken wires is critical when using this rope.
Due to its design, the 19 x 7 construction has a
relatively low reserve strength. This can result
in short service life between the point in time when
the broken wire removal criteria are met and when
actual rope failure occurs.
8 x 25 Resistwist ® rope
In a multi-part wire rope system where
the blocks have a tendency to twist -- or for a single-part
hoist line that doesn't require the degree of rotation-resistant
properties found in a 19 x 7 rope -- the 8 x 25 Resistwist
rope has found successful application. The rotation-resistant
characteristic is achieved by laying the eight outer
strands around an independent wire rope core so these
strands are in the opposite direction to the lay
of the core. Thus, when the rope is in tension, opposing
rotational forces are created between the core and
the outer strands.
Though not as rotation-resistant, the
8 x 25 Resistwist is more stable than a 19 x 7 rope.
It also has increased resistance to bending fatigue
and crushing. This is achieved through the use of
eight-strand construction with an independent wire
rope core.
Like any application where an installation's
rope type is changed, the 8 x 25 Resistwist rope
should be substituted only after carefully comparing
specifications and strength requirements.
