4.3 Removal from service, sling by sling

1 Alloy steel chain

Chain is the sling with the most numeric criteria, because a chain link's condition is measurable.

• Wear. 1910.184(e)(8): if the chain size at any point of the link is less than that stated in Table N-184-1, the chain is removed from service. The construction version, 1926.251(b)(5), points at Table H-1, maximum allowable wear at any point of link. Both are published in the standard itself, sized by nominal chain size.
• Wear, defective welds, deformation and increase in length. 1910.184(e)(3)(iii) requires the thorough periodic inspection to look for all four, and to remove the sling immediately where they are present. Stretch is the one people miss, because a chain that has been overloaded gets longer before anything else shows.
• Cracked or deformed master links, coupling links or other components — 1910.184(e)(9)(i).
• Hooks cracked, opened more than 15 percent of the throat, or twisted more than 10 degrees — 1910.184(e)(9)(ii).
• Heated above 1,000°F — permanently removed, 1910.184(e)(6). Above 600°F in service, the working load limits come down per the manufacturer.

And the repair rule that goes with it: worn or damaged chain slings are not used until repaired, and where welding or heat testing is involved, repair, reconditioning and proof testing must be done by the sling manufacturer or an equivalent entity — 1910.184(e)(7)(i). Mechanical coupling links and low carbon steel repair links may never be used to repair broken lengths of chain, (e)(7)(ii).

2 Wire rope, and the difference between the two standards

This is the one place where construction and general industry genuinely do not say the same thing, and getting it wrong in either direction is easy.

One is a proportion measured over a length; the other is a count within a lay. The rest of the general industry list is common ground and applies to any wire rope sling worth keeping:

• Wear or scraping of one-third the original diameter of outside individual wires — (f)(5)(ii).
• Kinking, crushing, bird caging or any other damage resulting in distortion of the wire rope structure — (f)(5)(iii).
• Evidence of heat damage — (f)(5)(iv).
• End attachments that are cracked, deformed or worn — (f)(5)(v).
• Hooks opened more than 15 percent of the throat or twisted more than 10 degrees — (f)(5)(vi).
• Corrosion of the rope or end attachments — (f)(5)(vii).

Plus the temperature rule that is separate from all of these: fiber core wire rope slings of all grades are permanently removed from service above 200°F — 1926.251(c)(14).

3 Metal mesh

1910.184(g)(9) lists seven conditions, and four of them are about the handles rather than the fabric — which tells you where metal mesh slings actually take their abuse.

• A broken weld or broken brazed joint along the sling edge.
• Reduction in wire diameter of 25 percent due to abrasion, or 15 percent due to corrosion. Two different numbers for two different causes.
• Lack of flexibility due to distortion of the fabric.
• Distortion of the female handle so the depth of the slot is increased more than 10 percent.
• Distortion of either handle so the width of the eye is decreased more than 10 percent.
• A 15 percent reduction of the original cross sectional area of metal at any point around the handle eye.
• Distortion of either handle out of its plane.

Repairs are manufacturer-only, and (g)(8)(ii) adds a documentation duty that is unique to this material: once repaired, each sling is permanently marked or tagged, or a written record kept, showing the date and nature of the repairs and who performed them, available for examination.

4 Natural and synthetic fiber rope

1926.251(d)(6) and 1910.184(h)(5) share the same six conditions, and they are the most qualitative list in the standard — which makes them the ones most often argued with.

• Abnormal wear.
• Powdered fiber between strands — the classic sign of internal abrasion, and invisible until you open the lay.
• Broken or cut fibers.
• Variations in the size or roundness of strands.
• Discoloration or rotting.
• Distortion of hardware in the sling.

Then the hardest rule of the five materials: 1910.184(h)(6) — only fiber rope slings made from new rope shall be used, and use of repaired or reconditioned fiber rope slings is prohibited. There is no path back. Temperature range without derating is −20°F to +180°F, and wet frozen slings are outside it whatever the air temperature says — 1926.251(d)(3).

5 Synthetic web

1926.251(e)(8) is five conditions long and every one of them is binary.

• Acid or caustic burns — which is also why the chemical rules in (e)(6) matter: nylon out where acids or phenolics are present, polyester and polypropylene out where caustics are, aluminium fittings out in caustics.
• Melting or charring of any part of the sling surface. "Any part" — a single glazed spot from a grinder counts.
• Snags, punctures, tears or cuts. No depth threshold. This is where edge damage from Part 3 shows up.
• Broken or worn stitches — the reason 1926.251(e)(5) makes stitching the only permitted method of forming eyes and attaching fittings.
• Distortion of fittings.

Web slings may be repaired, but only by a sling manufacturer or an equivalent entity, and each repaired sling must be proof tested to twice the rated capacity before returning to service, with the employer retaining the record — 1910.184(i)(8). Temporary repairs are prohibited outright by (i)(8)(iii). Temperature limits: polyester and nylon not above 180°F, polypropylene not above 200°F.

6 Two conditions that apply to everything

Whatever the material, two findings end the discussion before you reach the material-specific list.

1. 1
   No legible identification marking. 1926.251(a)(2)(iii) and 1910.184(c)(14): the sling may not be used, and there is no derating rule to fall back on.
2. 2
   Any damage or defect at all. 1910.184(c)(1) is broader than every list in this chapter: "Slings that are damaged or defective shall not be used." The removal paragraphs give you specific, defensible conditions; they do not license using a sling that is obviously wrong but does not match a bullet point.

The site's rigging gear inspection form turns these lists into a printable form, with each check carrying the paragraph it comes from.