Wire Rope Slings are made from quality wire ropes and end fittings, These slings are available against orders only with very short delivery period. Ropes are largely being converted into slings as slings find variety of applications in engineering industries, construction and material handling. In addition to standard slings, tailor made slings are made to cater specific applications. Slings are usually made out of high tensile ropes to make them light and incorporate high carrying capacity. Standards are available for the users to refer for fabrication, installation, usage and maintenance of slings.

Wire rope consist of three basic components, while few in number, these vary in both complexity and configuration so as to produce ropes for specific purposes or characteristics, The three basic components of a standard wire rope design are:

1) Wires that form the strand,
2) multi-wire strand: laid helically around a core, and
3) the core
 

slings are constructed to meet nearly every need. Of course, there are many special situations, which require the use of a specialty sling. These are also available when ordering a specialty sling be sure to consider:

• Maximum load
• Type of material to be handled
• Condition of material
• Lifting attachments
• Dimensions of load
• Height of lift
• Headroom and working space available
• Distribution of load weight
• Load center of gravity
• Number of sling legs required
• Ordering wire rope slings

When ordering slings specify the sling Diameter and length are required ; the dimensions and fittings indicated will be supplied. When variations are necessary full dimensions must be specified. For example alloy oblong links are standard or most bridle slings, and these will be supplied unless otherwise specified. If oblong or pear-shaped carbon Inks are desired, full link dimensions should be included.

Rated capacities

Rated capacities suggested for Lifting slings are based on sound engineering practices and ample design factors. And are in accordance with Occupation Safety and Health Administration standards. Rated capacities are only applicable for new slings under normal conditions. As a standard practice to avoid confusion.

Wire rope construction

Wire ropes, which are regularly used in Lifting slings, are either 6 x 19 Class 0r 6 x 37 Class. Generally. Ropes with diameters tip to 1 1/8 in. inclusive are 6 x l9 Class and ropes with larger diameters are 6 x 37 Class. The choice between the two classes may also depend upon the application of the sling, and the characteristics that are most desirable in the sling. For example, if resistance to abrasion is of prime importance, the 6 x 19 Class is chosen because wires of large diameter provide a high degree of wear resistance. On the other hand, if flexibility is desired, the 6 x 37 Class is more satisfactory because of the large number of smaller wires in the rope Other constructions may be available. but they are rarely used and will not be supplied unless specified.

Effect of lifting angle on Lifting Capacity

The rate capacity of a multiple leg sling is directly affected by the angle of the sling leg with the vertical. As this angle increases, the stress on each leg increases with the same load. If the sling angle is known, the capacity can be readily determined by multiplying the sling's vertical capacity by the appropriate load angle factor from the table below.

Example:

A multiple leg sling with a rated capacity of 2000 Kgs. will have a capacity of 1000 Kgs. (2000 x 0.500) when sling legs are at angle of 60° with vertical

Wire rope sling inspection

• Conditions such as the following should be sufficient reasons for consideration of sling replacement.
  randomly distributed broken wires in one rope lay.
• For cable laid and braided slings of less than 8 parts, twenty (20) randomly distributed broken strand per sling.
• For braided slings of 8 parts or more, forty (40) randomly distributed broken wires in one braid, or two (2) broken stands per sling.
• Severe localized abrasion or scraping.
• Kinking, Crushing, bird caging or any other damage resulting in distortion of the wire rope structure.
• Evidence of heat damage or if a wire rope sling having a fiber core is exposed to temperatures un excess of 200°F,  if a wire rope sling having a fiber core is exposed to temperatures in excess of 200oF, or if a wire rope sling having a steel core is used at temperatures above 400°F or below minus 60°F.
• End attachments that are cracked, deformed, or worn.
• Hooks that have been opened more than 15% of the normal throat opening measured at the narrowest point or twisted more than 10° from the plane of the unbent hook.
• Corrosion of the rope or end attachments.
• Unlaying or opening up of a tucked splice.