Wire rope clips are quite small in relation to an entire wire rope setup, but this small hardware piece plays a key role in security and durability. The role of the wire rope clip is to join the end of the wire rope securely to create a loop. This may be used for overhead lifting, along with other numerous purposes, like:
There are different design styles for wire rope clips, but all clips work similarly. There is a rounded opening that fits around the wire rope. The clip is closed by two screws with bolts, causing the rounded opening to tighten around the wire rope, holding it firmly in place.
Since this hardware is used in applications that involve heavy equipment, which can be dangerous, wire rope clips need to be used correctly. Here are the things to keep in mind for a safe wire rope installation:
First and foremost, make sure you’re using the correct wire rope clip type for the job.
There are two types of wire rope clip designs: U-bolt or double saddle. It should be noted that only drop forged U-bold wire rope clips are permitted for overhead lifting, double saddle clips are not.
A U-bolt clip is made with a U-shaped bolt, along with a metal base or saddle piece that fits around the wire rope. This is held in place with two nuts that screw on the bottom of the clip.
A double saddle wire rope clip is made from two separate bolts that are held in place by bolts on either side. This different design is somewhat easier to use, as there is no top or bottom. However, they have a lower load capability, which is why they aren’t recommended for rigging.
There are also several types of metals used to make wire rope clips. As mentioned, drop forged clips are the only type that is permitted for overhead lifting. This is made from molten steel that is shaped into place with a ram hammer, making it quite durable. This type of clip is also hot galvanized for additional protection and corrosion resistance.
Wire rope clips may also be purchased in stainless steel and malleable electro-galvanized options. While stainless steel is a very strong metal, it is considered soft and may bend under heavy-duty applications – which is why it shouldn’t be used for overhead lifting. Malleable wire rope clips may even fracture under heavy loads and are best used for light-duty applications like fencing.
The way that a wire rope clip is installed is extremely important, as the placement and angle can interfere with its strength and hold. Before installing, the wire ropes should be inspected and the clips should be checked for several things, including:
Remember to inspect the wire rope before adding the clips on as well. Without proper care or handling, wires in the rope may snap or corrode. Even though the wire rope clips may be in good shape, they won’t hold well if the wire rope is damaged.
Be sure to double-check all safety factor calculations as well. When clips are used to create a sling for overhead lifting, it diminishes up to 75% of the wire rope’s original working load limit. Keep this in mind!
The next step in wire rope clip installation is placement and securement. First, you will measure out the end length of the wire rope that will need to be secured with the clips. A heavy-duty thimble may be added inside of the loop for added support.
Next, undo the clips so they are separated into two parts and fit the U-bolt around the two wire ropes. Then, tighten both of the bolts evenly until they are securely fastened, holding the ropes firmly in place.
Multiple clips should be used for added security with space measuring between 1.5 to 3 times the length of the clip apart. All wire rope clips must be facing the same direction and should be evenly spaced apart.
The majority of issues come with not following the proper requirements for wire clip installation. Failing to follow the rules for spacing, placement, or using the wrong type of clip can be quite dangerous, causing the rope to slip.
Another common issue is not torquing the bolts correctly. This includes both under-torquing and over-torquing. If the bolts are too tight, they will actually wear down the threads of the wire rope beneath. Be sure to follow the manufacturer’s directions on the clips for proper torquing techniques.
Finally, wire rope clips will need to be retightened or cycled out. No bolts will stay perfectly in place for a prolonged period of time, especially if there is a high level of friction. Clips should also be relocated and cycled out after multiple uses.