How is the diameter of an elevator wire rope correctly measured?

Using a caliper with broad jaws, measured across the crowns of the outer strands.

What is the advantage of dual-tensile wire ropes?

They use lower tensile strength wires (e.g., 1370 N/mm²) on the outside for better wear resistance and reduced sheave wear, and higher tensile (e.g., 1770 N/mm²) on the inside for overall strength.

What types of cores are permitted?

Natural fiber (like sisal), synthetic fiber, or Independent Wire Rope Core (IWRC), chosen based on flexibility requirements and load.

IS 3534 Part 2

: 2010

Wire Ropes for Lifts — Part 2: Methods of Test

CurrentSpecializedSpecificationMEP · Lifts, Escalators and Mechanical Handling

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This standard prescribes the methods of test for determining the physical and mechanical properties of steel wire ropes used for suspension and compensation in lifts (elevators). It covers the measurement of rope diameter, actual breaking force, and mechanical tests on individual extracted wires.

Specifies the methods for testing steel wire ropes used in lifts.

Quick Reference Values

Tensile strength grade (Dual tensile)1370/1770 N/mm²

Tensile strength grade (Single tensile)1570 or 1770 N/mm²

Standard rope diameter tolerance+1% to +5% of nominal diameter

Maximum ovality toleranceMax 3% of nominal diameter

Key Formulas

F_min = (K * d^2 * R_0) / 1000 — Minimum breaking force calculation where K is the minimum breaking force factor

Practical Notes

Wire rope diameter must always be measured across the crowns (widest part) of the strands using a broad-jawed caliper, not in the valleys.

Elevator ropes typically experience 'constructional stretch' shortly after installation, requiring engineers to plan for tension adjustments or rope shortening.

Over-lubrication can cause slippage on the traction sheave; always use lubricants specifically formulated for traction elevators.