ISO 2408 / ASME B30.9 Compliant

Wire Rope Capacity
Calculator

Get breaking load, working load limit (WLL), and weight per meter for 6x19 IWRC, 6x36 IWRC, and 6x7 FC wire rope. No signup. No PDF. Just answers.

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🪢 Wire Rope Capacity Calculator

Based on ISO 2408 / ASME B30.9. Not a substitute for qualified rigger judgment. Always verify with manufacturer data.

Wire Rope Specification Tables

Complete breaking load and weight data for all standard diameters. ISO 2408 compliant, EIPS grade 1960 N/mm².

6x19 IWRC

Stiff, abrasion-resistant. General purpose rigging.

Ø (mm)Break (t)kg/m
62.40.13
84.20.23
106.50.36
129.30.52
1412.60.71
1616.40.93
1820.71.17
2025.51.45
2230.81.76
2436.62.10
2642.92.47
2849.72.87
3264.83.74
3681.94.73
40101.05.84

6x36 IWRC

Flexible. Cranes, winches & sheave applications.

Ø (mm)Break (t)kg/m
83.90.22
106.00.35
128.60.50
1411.70.68
1615.20.89
1819.21.13
2023.71.39
2228.61.68
2434.02.01
2639.92.36
2846.22.74
3260.33.58
3676.24.53
4094.05.60

6x7 FC

Very stiff. Static lines, guys & stays.

Ø (mm)Break (t)kg/m
41.10.06
51.70.09
62.40.13
84.30.23
106.70.36
129.60.52
1413.00.71
1617.00.93

Breaking loads are minimum values for 1960 N/mm² (EIPS) grade wire rope per ISO 2408. WLL = breaking load ÷ safety factor.

Which Wire Rope Construction?

Breaking strength is similar for the same diameter — the difference is flexibility, abrasion resistance, and fatigue life.

6x19 IWRC
Stiff & Abrasion-Resistant
  • Best wear resistance of the three
  • Resists crushing on drums
  • Good for general rigging & slings
  • Less flexible — larger sheave diameters needed
Typical: hoist ropes, slings, winch lines with infrequent bending
6x36 IWRC
Flexible — Cranes & Winches
  • Most flexible of the three
  • Best fatigue life over sheaves
  • Standard for crane hoist ropes
  • Wears faster than 6x19 in abrasive conditions
Typical: tower cranes, mobile cranes, high-cycle winches
6x7 FC
Very Stiff — Static Lines
  • Cheapest construction
  • Excellent stability on drums
  • Good for guys, stays, hand ropes
  • Poor flexibility & fatigue life — never over sheaves
Typical: guy wires, guard rails, static mooring lines

Wire Rope Safety Factor Guide

WLL = Breaking Load ÷ Safety Factor. Choose based on your application and local regulations.

3.5:1
Specialized Equipment

Permitted for certain cranes and winch applications under specific standards (e.g. some EU machinery directives). Never assume 3.5:1 is acceptable — verify with the equipment manufacturer and applicable code.

5:1
General Lifting — ASME B30.9 Minimum (DEFAULT)

The standard minimum for wire rope used in lifting service. Applies to slings, hoist ropes, and rigging. When in doubt, use 5:1.

10:1
Critical Lifts & Personnel

Used for lifts where failure would be catastrophic, man-riding applications, or where shock loading is possible. Many offshore and nuclear applications require 10:1 or higher.

⚠️ A safety factor below 5:1 for general lifting is below the ASME B30.9 minimum. This calculator will warn you — but the final responsibility rests with the qualified person planning the lift.

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Frequently Asked Questions

Answers based on ISO 2408 and ASME B30.9 standards.

What is the minimum safety factor for wire rope used in lifting?+

ASME B30.9 recommends a minimum 5:1 safety factor for wire rope in lifting service. Some specialized equipment uses 3.5:1, and critical lifts may require 10:1. Always verify with your engineering team and applicable regulations.

What is the difference between breaking load and WLL?+

Breaking load (minimum breaking strength) is the load at which the rope fails. WLL is the maximum permissible working load: WLL = breaking load ÷ safety factor. For a 20mm 6x19 IWRC rope with a 25.5t breaking load at 5:1, WLL = 5.1 tonnes.

What is the difference between 6x19 and 6x36 wire rope?+

6x19 has 19 wires per strand — stiffer, more abrasion-resistant, good for general rigging. 6x36 has 36 wires per strand — more flexible, better fatigue life over sheaves, ideal for crane hoist ropes. Breaking strength is similar for the same diameter. See our Wire Rope Size Chart for full data.

When should I use 6x7 wire rope?+

6x7 is the stiffest common construction. Use it for static lines, guy ropes, and stays where the rope won't bend over sheaves. Never use 6x7 in high-cycle bending applications — the wires fatigue quickly.

Disclaimer: All calculations are for reference only and based on ISO 2408 minimum breaking loads for 1960 N/mm² (EIPS) grade wire rope. Actual breaking loads vary by manufacturer, lay, and grade. Always verify with manufacturer certificates and have a qualified person plan every lift. riggingcalculators.com accepts no liability for use of these calculations.

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