WIRE ROPE TERMINATION
To be a wire-rope rigger or end user, you must be aware of all the different types of wire-rope terminations, or treatments, that are available. To provide a long-term connection between the wire rope and its load, these terminations typically include an eye or some other type of fitting.
As a mechanical device, wire rope can be used to support and move an object or load. With swivels, shackles, or hooks, wire ropes are used in the lifting and rigging industries to attach to a load and move it precisely. Elevators can be raised and lowered with the help of this device, as well as suspension bridges or towers.
We’ll go through the definitions of the following terminology and how they can be utilized to finish off a wire rope cable in this article:
- Wire rope sockets—spelter sockets, swaged sockets, and wedge sockets
- Wire rope clips—U-bolt wire rope clips and double saddle wire rope clips
- Eye splices—mechanical (Flemish) and hand-tucked splices
- Wire rope end termination efficiencies
Termination options
In order to terminate a piece of wire rope or cable, there are two primary methods:
An eye or loop can be formed in the wire rope.
The end of the wire rope can be fitted with a swivel.
This can be done by either utilizing an eye or loop at one end of the rope, which can be done by hand-tucking the end of the wire or by using an eye.
Swaging, pouring molten zinc or resin that bonds to the wires, or employing a wedging arrangement are all methods for attaching fittings to wire rope.
Ending a wire rope cable with a termination fitting is known as socketing.
With a variety of means, a socket can be joined to a wire rope cable’s end.
Pressure exerted by a hydraulic cylinder.
When molten or epoxy-like substances are poured A mechanical wedge can be used for this purpose.
When deciding between a poured or swaged socket, keep in mind that both types are available in open or closed configurations.
In an open socket, the wire rope assembly can be attached to another form of fitting, such as a hook block.
To use a closed socket fitting, you must first remove the cover from the socket.
To secure a wire rope cable, a specific die and hydraulic equipment called a swager are used to drive the socket into position. Swaged sockets offer an efficiency rating of 100% of the rope’s breaking strength when applied correctly with the correct sized fitting.
At the point where the cable and socket meet, swaged fittings are more resistant to wire fatigue.
Fiber core and long lay wire rope cables should not be connected using swaged sockets.
It is a type of socket known as a spelter socket that is used to attach a cable termination fitting to the end of a wire rope by pouring hot molten zinc or resin into the end of the cable.
When it comes to end attachments, poured sockets outperform all others, delivering a full 100 percent of their claimed breaking strength.
If the poured socket is subjected to constant vibration, the wires of the rope are at risk of fatigue because of the rigidity of this type of termination.
By passing the rope around a grooved, wedge-shaped piece of steel and drawing it into the bowl of the fixture, wedge sockets secure the end attachment.
In the field, wedge sockets can be placed and adjusted to provide 80 percent efficiency in rope breaking strength, making them a popular choice. Wire rope can be subjected to a lot of abrasion and abuse in construction and mining applications, hence wedge sockets are preferred.
Wire rope cable length can be adjusted using wedge sockets in the event that matched sets of crane cables are unavailable.
Wire rope sling eyes of the Flemish type are formed by looping an eye and securing a sleeve to the rope at the base of the loop. Splicing the ends of the rope strands together by swaging them creates a streamlined, compact, solid, and long-lasting joint. There are no rope distortion, wire ends, or risks of rope slippage due to rotation with Flemish wire rope sling eyes. The Flemish Eye ensures equal distribution of the load in both parts of the eye because the pull is directly along the rope and eye’s center line. For maximum efficiency, the National S-505 Standard Steel Sleeve can be cold-swaged to form an extremely strong bond around the splice, which is close to the wire rope’s rated breaking strength.
Engineered for cold swaging in both extreme hot and cold environments, the National S-505 COLD TUFF® Steel Sleeve can be cold swaged without failure. Tapered at one end, the sleeves are designed to avoid snagging when passing under obstacles. The other end has a radius that prevents rope abrading from occurring.
Wire rope end terminations for both independent wire rope core (IWRC) and fiber core (FC) wire rope topologies are shown in the table below. Efficiencies of wire ropes can be stated as a percentage of a wire rope’s actual breaking strength compared to the aggregate strength of all wires evaluated individually.
| IWRC | FC | |
| Hand-Tucked Splices | 80–90% | 80–90% |
| Mechanical Splices | 90–95% | 90–92.5% |
| Swaged Steel Fittings | 95–100% | 90–95% |
| Poured (Spelter) Sockets* | 100% | 100% |
| Wire Rope Clips** | 80% | 80% |
| Wedge Sockets | 75–90% | 75–90% |