Slings: marking, requirements, decoding

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

Lifting operations are mostly directly related to the use of special industrial products called slings. These elements for lifting/lowering various objects are manufactured in strict accordance with state standards and undergo appropriate certification at narrow-profile enterprises. Slings, their varieties and designation rules will be discussed in this article.

General information

Sling marking is mandatory. Each of these lifting devices can basically have a cable, a rope, a chain or an element created on the basis of a special matter. The use of slings is carried out in almost all sectors of the national economy: in construction, in the manufacturing sector, in agriculture, navigation, etc.

Rope type slings

These slings are able to withstand extremely low temperatures (up to -40 degrees Celsius) and very high rates (within 400 degrees). The rope itself consists of many metal wires, securely woven together using a special technology.

Configurationrope slings allows you to easily diagnose the degree of wear during operation, which prevents the likelihood of a sharp rupture of these devices. In addition, the wire steel rope has the ability to smooth out emerging dynamic loads and therefore has a very long safe operation life.

Marking of rope slings provides for the following alphanumeric designations:

• 1SK - the lanyard has one branch.
• 2 SC is a two-branch model widely used in manufacturing workshops or warehouses.
• 4 SK - four branches of the sling are fixed on a special ring. This design of the lifting element has proven itself well on construction sites, where huge slabs and blocks often need to be moved.
• VK - the ends of this type of sling are sealed either by crimping or braiding.
• SKK - ring option.
• SKP - loop performance.

Operating Rules

Sling markings are just the tip of the iceberg. You should always remember about the rules for using lifting products. To do this, you must strictly comply with the following requirements:

• The condition of the slings is checked within the time specified in their technical data sheet.
• It is strictly forbidden to use a sling if there are any signs of mechanical damage, there is no tag if a scheduled inspection has not been carried out.
• If the sling is used at a temperature of more than 1250 degrees Celsius, its carrying capacity will decreaseby 25%.
• Strictly follow the load slinging scheme to ensure the safety of the operating personnel.
• Do not allow movement, slipping of the sling on the lifted load during its movement.

Chain Patterns

Chain slings are best for handling loads with sharp edges. These devices are made from steel links, which, in turn, are connected to each other by welding. As a result, the resulting design has high strength, reliability, flexibility and ease of use. A chain sling is also good because it is not afraid of high or low temperatures, exposure to acid or open fire. However, compared to the rope counterpart, the chain version will have much more weight.

The marking of slings created from the chain is as follows:

• 1 ST is a one-leg option.
• 2 SC - two-leg design of the sling eliminates breaking chain links.
• 4 SC - the so-called spider. A 4-leg sling used for handling irregularly shaped loads.
• ВЦЦ - a chain branch, which is a spare part for the repair of a sling, however, it can also be used as an independent load-lifting element.
• STs - ring version or universal.

Notation Features

Modern requirements for marking slings state that the following information must be on the tags attached to them:

• View. It implies an indication of the material from which the sling is made and the number of its branches.
• Capacity rating (in tons).
• Length in millimeters.
• Serial number assigned to the sling at the enterprise and indicated in a special journal.
• Date when the lifting element was tested at the factory.
• Manufacturer's name.

Manufacture and marking of slings provides that tags for chain and rope slings are necessarily made of metal - stamped alloy steel. All the required information is applied to them in a shock or shock-dot way.

Metal tags are not hung on a textile sling, but vinyl sewn-in copies are used. Data on such tags is applied using indelible ink through thermal printing.

In the manufacture of braided rope slings, the tag is woven directly into the body of the product. If the sling is pressed, then the tag is fixed on a special small loop.

Chains are tagged using a collar on a hanging link.

Textile patterns

The outstanding feature of these flexible load handling devices is their great versatility.

Marking of textile slings has a similar principle with chain and rope options and provides for the designation on the tag of the load capacity, length, type of loop and type.

In general, there are two main designations:

• STK - stands for textile ring sling. Can be made from one or more layers.
• STP - textile sling. Can also be single layer or multi layer.

Nuances of production and verification

Requirements for the manufacture, testing and marking of slings state that the safety margin of the steel rope in relation to the load of each strand must be at least 6.

Chain slings must be constructed from round link chain only. The safety factor of such slings should be kept at least 4.

When designing and manufacturing slings based on hemp, cotton or synthetic material, it is important to adhere to a safety factor of at least 8.

It is important to know that, regardless of the type of sling, they cannot be repaired, and after manufacturing they must certainly be tested with a load exceeding their stated in the passport by 25%.

Slings (marking, their decoding is given above in the article) in the case of individual production must undergo a mandatory check of all their elements. If lifting devices are mass-produced, then at least 2% of copies from each batch of manufactured elements are subjected to verification, but at the same time at least two pieces.

During the static testing of the slings, the inspector must visually and finally verify that there are no permanent deformations, cracks on the surface, or displacement of the rope in its attachments.

Movecargo with slings

To transport objects with sharp edges using rope-type slings, it is necessary to place special spacers made of wood, rubber, metal between the slings and the ribs of the load, which serve to prevent damage to the rope.

If a chain sling is used, then it is extremely important to avoid any kink of links on the ribs of the transported load.