You’ve got to regularly inspect your industrial lifting slings to ensure they are still safe to use. But how often should you examine them? And how do you know they need to be replaced?
If your lift slings fail, the repercussions are going to be serious — and maybe even deadly. That’s why it’s important to inspect your lift slings on a regular basis. OSHA recommends you inspect these critical components before use each day.
Inspecting Lift Slings
The first rule of inspecting lift slings is easy: don’t wait until something goes wrong. Every time you get ready to hoist a load with a lifting sling, that sling needs to be visually inspected. You need to verify that it hasn’t been damaged — and what you’re looking for is going to vary according to what kind of sling it is.
There are also periodic inspections that need to take place, with both OSHA (Occupational Safety and Health Administration) and ASME (The American Society Of Mechanical Engineers) discussing the frequency of sling inspection.
OSHA 1910.184 deals with slings, and 1910.184(d) provides specific information about when your lifting slings should be inspected:
- Slings, fastenings, and attachments are to be inspected for damage or defects before use each day
- Additional inspections are to be performed during sling use where conditions warrant
- Any sling that is damaged or defective is to be immediately removed from service
And additional information for steel alloy chain slings is given in 1910.184(e)(3)(i) that states a thorough periodic inspection should be made regularly. How often this takes place is dependent on …
- How frequently the sling is used
- How severe the service conditions are?
- The type of lifts being made with the sling
- The experience by the inspector on the service life of slings used in similar circumstances
- These periodic inspections should not take place less frequently than annually
The ASME B30.9-2018: Slings standard also describes how frequently slings should be inspected. They break down the frequency in terms of service. Normal service slings are inspected yearly, and severe service slings are inspected between monthly and quarterly. ASME also requires an initial inspection that takes place before slings go into service.
When to Replace Lifting Slings
Industrial lift slings should be replaced BEFORE they break. You should be performing regular inspections on them so that you can recognize when a sling needs to be taken out of service. Remember: Damaged or defective slings should be taken out of service immediately. So, what constitutes a damaged or defective sling? That depends on the type of sling.
First, a sling should always be replaced if its identification is illegible or missing. And if you see any damage that makes you question if it’s safe to use, then you’re better of replacing it.
Oh, and don’t forget to inspect the hooks!
Alloy Sling Chains
Alloy sling chains should be replaced when any of these issues are found:
- Defective welds or the presence of weld spatter
- Signs of deformation, brakes, or cracks
- Excessing corrosion or pitting
- Chain links or fittings that are deformed, bent, twisted, or stretched
- Inability of a chain or fitting to hinge (i.e., articulate freely)
- Increases in normal length
- Evidence of heat damage
In addition, there are some rules regarding chain size. Table N-184-1 of the OSHA standard gives the minimum allowable chain size in inches. If the chain size at any point of the link is less than that value, it must be removed from service.
Furthermore, remove the sling chain from service if the coupling links, master links, or other sling chain components are either deformed or cracked. And here are issues with hooks that mean an alloy sling chain should be removed from service:
- Opened more than 15% of the normal throat opening when measured at its narrowest point
- Twisted more than 10 degrees from the plane of the hook when it is unbent
Wire Rope Slings
Here are the guidelines for when to replace a wire rope sling:
- Broken wires (both OSHA and ASME provide details on what to look for)
- Distortion of the wire rope structure that takes the form of crushing, kinking, bird-caging, or other damage
- Severe corrosion of the rope itself or of the end attachments
- End attachments that are worn, deformed, or cracked to the extent that they affect the strength of the sling
- Evidence of wear or scraping that amounts to one-third of the original diameter of outside individual wires
- Evidence of heat damage
The rules for hooks are the same as those found under alloy sling chains.
Metal Mesh Slings
For metals mesh slings, these conditions indicate that the lifting sling needs to be replaced:
- A broken brazed joint or weld located along the sling edge
- Lack of flexibility due to fabric distortion
- Reduction in wire diameter of
- 15% due to corrosion
- 25% caused by abrasion
- Distortion so that …
- The depth of slot on the choker fitting has increased more than 10%
- The width of the eye of either handle has decreased more than 10%
- Either handle is out of its plane
- Any point around the handle eye that shows a reduction of 15% from the original cross-sectional area
- Components that are cracked, bent, or broken
Natural and Synthetic Fiber-Rope Slings
Here are the signs that a natural or synthetic fiber-rope sling should be replaced:
- Fibers that have been cut, broken, or gouged
- Rotting or discoloration
- Presence of powdered fiber between strands
- Size or roundness of strands shows variation
- Abnormal wear
- Distortion of hardware in the sling
For synthetic fiber-rope slings, there are some additional criteria for removal:
Synthetic Web Slings
Synthetic web slings should be replaced when they have these characteristics:
- Evidence of burns (acid or caustic), melting, or charring
- Stitches that are worn or broken in load-bearing areas
- Evidence of cuts, snags, tears, or punctures
- Knots anywhere in the sling
- Fittings that are distorted (e.g., bent, twisted), cracked, gouged, or broken
- Fittings that are corroded or pitted
- Areas of the sling that are stiff, brittle, or discolored
There are specific rules outlining when industrial lift slings need to be inspected as well as specific things to look for that will indicate a sling needs to be replaced. If you’re concerned about lifting sling inspections and replacement, let the experts at Hi-Speed Industrial Service help. Our team of trained inspectors can advise on how often your lift slings need to be inspected. They can also perform the appropriate periodic inspections according to OSHA/ASME standards and advise when lifting slings need to be replaced.