Accoloy Kuplex Oblong Master Links
Peerless Oblong Master Links
V10 Alloy (Grade 100) Oblong Master Links
Nominal Sling Strength is the angle measured between a horizontal line and the sling leg of the body. This angle is very important and can have a dramatic effect on the rated capacity of the sling. As illustrated above, when this principle applies whether one sling is used to pull at an angle, in a basket hitch or for multi-legged bridle slings. Sling angles of less than 30 degrees are not recommended.
NOMINAL SPLICE EFFICIENCY
Nominal Splice Efficiency is the efficiency of the sling splice. Any time wire rope is disturbed such as in splicing an eye, the strength of the rope is reduced. This reduction must be taken into account when determining the nominal sling strength and in calculating the rated the capacity. Each type of splice has a different efficiency, thus the difference in rated capacities for different types if slings. Nominal splice efficiencies have been established after many hundreds of tests over years of testing.
D/d ratio is the ratio of the diameter around which the sling is bent divided by the body diameter of the sling (Figure 4). This ratio has an effect on the rated capacity of the sling only when the sling is used in a basket hitch. Tests have shown that whenever wire rope is bent around a diameter the strength of the rope is decreased. Figure 5 illustrates the percentage of decrease to beexpected.
This D/d ratio is applied to wire rope slings to assure that the strength in the body of the sling is at least equal to the splice efficiency. When D/d ratios smaller than those listed in the rated capacity tables are necessary, the rated capacity of the sling must be decreased.
MECHANICAL SPLICE slings come in two basic types. One being the Returned Loop and the other the Flemish Eye or farmers splice. In either case, the splice is com- pleted by pressing (swaging) one or more metal sleeves over the rope juncture.
The returned loop is fabricated by forming a loop at the end of the rope, sliding one or more metal sleeves over the short end of the loop eye and pressing these sleeves to secure the end of the rope to the sling body. This makes an economical sling and in most cases one that will give satisfactory service. A drawback to this type of sling is that the lifting capacity of the sling depends 100% upon the integrity of the pressed or swaged joint. Should the metal sleeves(s) fail, the entire eye will also fail.
The flemish eye splice is fabricated by opening or unlaying the rope body into two parts, one having three strands and the other having the remaining three strands and the core. The rope is unlayed far enough back to allow the loop or eye to be formed by looping one part in one direction and the Flemish eye spliceother part in the other direction and lay- ing the rope back together. The strands are rolled back around the rope body. A metal sleeve is then slipped over the ends of the splice and pressed (swaged) to secure the ends to the body of the sling. Nominal splice efficiencies expressed in table 4 and in the rated capacity tables are based on this splicing method. Splice efficiencies for other splicing methods should be confirmed by the sling manufacturer. Notice that the splice efficiency factor plays no role in the calculation of the Choker Hitch rated capacity. This is because as the rope passes through the eye of the sling in a choke, the weakest part of the sling is in the body of the sling at the choke point. Thus the splice being higher in efficiency, has no effect on the rated capacity, because the efficiency factors are not additive. Rated capacities for single part, choker and basket hitches are calculated exactly the same as for hand tucked slings except for the nominal splice efficiencies. The rated capacities adjustment table 1 for choker hitches also applies for mechanical spliced slings. Minimum D/d ratio for basket hitches is 25. This larger D/d ratio is required because the Nominal Splice Efficiency is higher.
Construction or Classification
- 6 x 7 class (6 strands of 7 wires)
- 6 x 19 class (6 strands of 9 – 26 wires per strand)
- 6 x 37 class (6 strands of 27 – 49 wires per strand)
- 8 x 19 class (rotation resistant)
- 19 x 7 class (rotation resistant)
- 35 X 7 class (High Performance Ropes)
- 7 x 19 construction
- 7 x 7 construction
- 1 x 19 strand
- 1 x 7 strand
Wire Rope Core
FC (Fiber Core: manila or sisal)
IWRC (Independent Wire Rope Core)
Lay Direction / Lay Type:
- RRL (Right Regular Lay)
- LRL (Left Regular Lay)
- RLL (Right Lang Lay)
- LLL (Left Lang Lay)
- IPS (Improved Plow Steel) or 1760 N/mm2 or Grade110/120
- EIPS (Extra Improved Plow Steel) or 1960 N/mm2 or Grade 115/125
- EEIPS (Extra Extra Improved plow Steel) or 2160 N/mm2 or Grade 130/140
- Drawn Galvanized
- PVC Coated