Training plays a vital role in the proper selection, use and maintenance of slings. Most manufacturers offer courses that will provide distributors and their customers information on slings, including:

• Types and benefits of each sling type
• Typical users of each type of sling
• ANSI, OSHA, and ASME standards related to slings
• Accessories such as hooks, spreader beams and wear pads typically used with slings
• Basic rigging techniques
• Proper identification tags/labels
• Inspection types and procedures

Distributor training classes can range from basic courses to full-day, in-depth courses. The basic classes will help distributor personnel assist customers with application and sling selection. The in-depth courses are for those wishing to offer customers a sling inspection service and/or have in-house production and service departments.

When selecting an in-depth training course, make sure it provides hands-on work during the session. This experience allows the attendee to gain a better understanding of the applications and closely examine the materials they may encounter in the field.

There are three basic types of slings: chain, wire rope and synthetic. Each has its benefits and disadvantages. The chart below shows some of the basic differences between these sling types.

When helping a customer select a sling for a lifting application, distributors should consider the following:

• Weight of load
• Width x height x length of load
• Center of gravity
• Number of pick points
• Ambient conditions in which sling will be used
• Size of crane hook or attaching point
• Upper and lower fittings
• Type of load movement
• Other equipment used in conjunction with the sling, such as lifting beams, spreader bars and hoist

With this information, a trained distributor or manufacturer will be able to start the selection and/or design process for the application. Additional information may be needed to ensure safe and efficient material handling.

Regardless of the type of sling, there are certain standards that must be met. ASTM, ASME, and OSHA sling standards require that slings be tagged with the rated load and angle, reach, size, grade (for chain) and name of manufacturer. It is recommended that the sling also include a serial number recorded by the manufacturer. This helps ensure the quality of the product, which is of great importance for products used in lifting applications.

The first step in inspecting chain is to identify it by its embossing. Make sure the chain is grade 63, 80 or 100—only these grades are allowed for lifting applications. All slings must have a durable tag with size, reach, working load limit at 90 degrees on single and 60 degrees from horizontal on multiple-leg slings, serial number, manufacturer and number of branches.

Visually inspect all chain before use. For a meaningful examination, the chain should be cleaned to permit proper viewing of its links. Examine each link for the following conditions: twists or bends, nicks or gouges, excessive wear at bearing points (interlink area), elongation, corrosion and heat damage.

OSHA regulation 29 CFR 1910.184 states that once an alloy chain sling reaches 1,000°F it must be removed from service. Since any of these conditions can affect the chain’s performance and/or reduce the chain’s strength, chains containing any of these conditions may be a safety hazard. A qualified person should examine the chain, assess the damage, and make a decision on whether or not repair is necessary before returning it to service. Extensively damaged chain should be scrapped. Always use the wear criteria of the chain’s manufacturer. Each manufacturer has different wear allowances.

A wire rope is a piece of flexible, multi-wired, stranded machinery and may contain hundreds of individual wires, which are formed and made to operate as one unit. The wire rope core forms a foundation for the strands and may be made of a fiber rope, an Independent Wire Rope Core (IWRC) or a strand similar to the outer strands of the rope. The greatest differences in wire ropes are found in the strands, which may vary widely in the pattern and number of wires that are laid together. The majority of the wire rope used is right lay, regular lay. This specification has the widest range of applications and meets the requirements of most equipment.

Inspect wire rope for crushed wires, broken wires, doglegs or kinks, abrasion and heat damage. Wire rope’s maximum operating temperature is between 200°F (for IWRC) – 400°F, depending on the type of core. Lubrication is critical; wire rope can suffer from internal corrosion. If you see a reduction in area, suspect that the rope is suffering from internal corrosion. Remove it from service if you find 10 randomly distributed broken wires in one rope lay, or five broken wires in one strand in one rope lay.

Synthetic slings such as polyester, nylon, web and round slings are very popular with riggers. They are lightweight, easy to rig and help reduce load damage.However, out of all types of sling, polyester will have the least amount of service life and should be inspected regularly. It has low heat resistance (194°F) and is subject to damage from chemicals, cuts and abrasions. The sun’s UV rays also break down the fibers.

Often times, users misuse their nylon slings by knotting them to shorten them. This is not an acceptable practice. Any synthetic sling that has knots, abrasions, damage, cuts, snags, heat damage or red warning fibers starting to show should be removed from service immediately.

All types of sling should undergo both frequent and periodic inspections. These terms, as well as who should perform inspections, are defined by the ASME standards. It is imperative that any sling found to have signs of damage or deformation be discarded and replaced with a new sling. By becoming knowledgeable on sling selection and maintenance, a distributor can help customers to make work environments safer and more productive.

Columbus McKinnon offers a wide variety of training, including sling selection and inspection courses. For more information, call 800-888-0985 or visit www.cmindustrial.com.