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Key Criteria for Replacement Crane Wire Rope (The “10-2-1” Rule is a good start)

A common and easy-to-remember guideline is the “10-2-1” Rule, but it’s just the beginning.

1. Broken Wires (The “10” and “2”)

• Random Broken Wires: The rope must be replaced if the number of randomly distributed broken wires in one rope lay (the length it takes for one strand to make a complete spiral around the core) reaches 10.
• Broken Wires in a Strand: If 2 or more broken wires are found in one strand within one rope lay, the rope must be replaced. This indicates a localized problem or “birdcaging” in that specific strand.

2. Wear and Corrosion (Reduction in Diameter)

• Loss of Metallic Cross-Section: Measure the rope diameter. If there is a loss of more than 1/3 of the original nominal diameter due to wear, 腐食, or core failure, the rope must be replaced. This is a critical sign of strength loss.

3. 腐食 (The “1”)

• Heavy Corrosion: The rope must be replaced if there is evidence of any pitting or severe corrosion that has weakened the rope. This is a standalone reason for replacement, regardless of broken wires.

Other Critical Reasons for Immediate Replacement

Beyond the “10-2-1” rule, look for these specific types of damage:

• 1. Heat Damage: Any evidence of exposure to high heat (例えば。, from a fire or being near welding). This can be identified by a blue-black discoloration and loss of lubricant integrity. The rope’s strength is permanently compromised.
• 2. Kinking, Crushing, or Birdcaging: Any distortion that changes the rope’s geometry. A “kink” creates a permanent weak point. “Birdcaging” (where strands are forcibly pushed out from the core) indicates severe shock loading or mechanical damage.
• 3. Damaged or Pushed-Out Core (Core Protrusion): If the core is visibly protruding from the strands, the rope’s internal support is gone.
• 4. Electric Arc Damage: If the rope has been part of an electrical fault, it can have melted or burned spots, severely weakening it.
• 5. Severe Localized Wear (Scrubbing): Excessive wear at points where the rope contacts other ropes, drums, or sheaves, especially in a single spot.
• 6. Reduction of Rope Diameter at an End Fitting: This can indicate core failure or corrosion inside the socket.
• 7. Excessive Stretching: If the crane wire rope has permanently elongated, it indicates that the wires have yielded and lost their strength.

Summary: When to Replace – Crane Wire Rope Quick Checklist

Condition	Action – REPLACE THE ROPE
10 or more broken wires in one rope lay.	YES
2 or more broken wires in one strand in one rope lay.	YES
Rope diameter is reduced by over 1/3 from its original size.	YES
Any signs of severe corrosion or pitting.	YES
Evidence of heat or electrical damage.	YES
Kinks, crushing, birdcaging, or any distortion.	YES
Damaged end attachments (例えば。, cracks in sockets).	YES
Core failure or protrusion.	YES
Worn-out or cracked outer wires (even if not broken).	Consult a qualified inspector immediately.

Always follow the manufacturer’s guidelines and comply with local safety regulations (OSHA, asme, 等). Formal inspections must be performed by a designated and qualified person.

For detailed information on crane wire ropes, please refer to: Crane Wire Rope