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SLINGS
WIRE ROPE
GENERAL INFORMATION
TABLE 4
NOMINAL SPLICE EFFICIENCIES
MECHANICAL SPLICED SLINGS
IMPOVED PLOW STEEL
6X19 AND 6X37 CLASS ROPES
Diameter
IWRC
FIBER CORES
1/4" through 1"
0.95
0.925
1 1/16" through 2"
0.925
0.9
2 1/16" & larger
0.9
Not Established
EXTRA IMPROVED PLOW STEEL:
1/4" through 1"
0.95
1 1/16" through 2"
0.925
2 1/16" & larger
0.9
STAINLESS STEEL, 302 & 304 GRADE:
1/4" through 1"
0.95
1 1/16" through 2"
0.925
2 1/16" & larger
0.9
Notice that the splice efficiency factor plays no role in the
calculation of the Choker Hitch rated capacity. This is
ZINC OR RESIN POURED SOCKET TYPE
because as the rope passes through the eye of the sling in
TERMINATIONS
a choke, the weakest part of the sling is in the body of the
While some people may debate whether zinc or resin
sling at the choke point. Thus the splice being higher in
poured sockets are truly slings, they are generally included
efficiency, has no effect on the rated capacity, because the
in the sling category. This type of termination has tradi
efficiency factors are not additive.
tionally been the method for determining the rope's actual
breaking strength. All other types of end terminations
Rated capacities for single part, choker and basket hitches
have been compared to poured sockets. Their efficiency
are calculated exactly the same as for hand tucked slings
is therefore established to be 100% for all grades and
except for the nominal splice efficiencies. The rated
constructions of rope.
capacities adjustment table 1 for choker hitches also
applies for mechanical spliced slings. Minimum D/d ratio
Choker hitches are not used as much with poured sockets
for basket hitches is 25. This larger D/d ratio is required
as which the other more general types of slings. When
because the Nominal Splice Efficiency is higher.
such slings are used in a choker hitch, the rated capacity
adjustment table 1 applies.
GENERAL PRECAUTIONS
Are no different from other slings except care should be
Rope assemblies with poured attachments are generally
taken not to deform or damage the sleeve.
used as a straight tension member where the rope body
does not contact the load and is otherwise kept free from
Stainless Steel slings which have sleeves made of a differ
distortion or physical abuse. In such cases the minimum
ent grade or type metal than the rope body may experi
recommended design factor is 3.0. If the assembly is
ence accelerated deterioration due to an electro chemical
used as a sling then a design factor of 5.0 should be used
reaction between the two metals. This is particularly evi
to calculate the rated capacity. Rated capacities for these
dent in salt water or brackish conditions.
slings used in basket hitches are the same as mechanical
spliced slings and use the same D/d ratio factors.
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