What are the categories of wire rope?

Wire ropes are essential components in various industries, including elevators, construction, mining, marine, and aviation. They are designed to withstand heavy loads and dynamic stresses, making them indispensable in lifting, traction, and suspension systems. To ensure proper selection and application, it’s crucial to understand the classification, marking codes, and common types of wire ropes.

1. Classification of Wire Ropes

Wire ropes can be classified based on multiple factors, including structure, diameter, application, surface condition, strand shape, and core type.

1.1. By Structure

Single-Strand (Single-Twist) Wire Rope

Includes standard single-strand, semi-sealed, and fully sealed wire ropes. These are made by twisting individual wires together into a single strand.

Multi-Strand (Double-Twist) Wire Rope

Formed by twisting several strands around a central core in a helical pattern. This is the most common structure used in elevators, cranes, and hoisting applications.

Three-Strand (Cable-Laid) Wire Rope

Constructed by twisting multiple wire ropes around a fiber or steel core. This type of rope is often referred to as a cable and is used in heavy-duty and specialized industrial applications.

1.2. By Diameter

Fine Wire Rope -Diameter less than 8 mm, used for light-duty applications such as control cables or small lifting devices.

Standard Wire Rope-Diameter between 8 mm and 60 mm, commonly used in elevators, cranes, and hoisting systems.

Heavy-Duty Wire Rope -Diameter greater than 60 mm, suitable for deep mining, offshore drilling, and heavy industrial use.

1.3. By Application

Wire ropes are used across multiple fields, including:

General-purpose lifting and hoisting

Elevator systems (Elevator Wire Rope)

Aerospace and aviation cables

Deep drilling and mining equipment

Marine and offshore applications

1.4. By Surface Finish

Ungalvanized Wire Rope -Offers good flexibility but limited corrosion resistance.

Galvanized Wire Rope-Coated with zinc to resist corrosion; ideal for outdoor and humid environments.

Plastic-Coated (PVC/PE) Wire Rope -Provides superior corrosion and wear resistance, often used in marine or safety applications.

1.5. By Strand Cross-Section Shape

Round Strand Wire Rope -Most common type, featuring circular cross-sections.

Shaped Strand Wire Rope -Includes flattened or compacted strands designed for higher strength and smoother surfaces.

1.6. By Contact Type

Point Contact Wire Rope (PSC)-Wires contact at single points; flexible but wears faster.

Line Contact Wire Rope (LRC)-Wires have line contact, providing better wear resistance.

Surface Contact Wire Rope (FRC)-Wires have surface contact, maximizing durability and load capacity.

1.7. By Lay Direction

There are four main lay directions used in rope construction:

These affect the rope’s flexibility, wear characteristics, and suitability for different applications.

1.8. By Core Type

Wire rope cores are divided into two main categories:

Fiber Core (FC)-Made of natural or synthetic fibers; provides lubrication storage and flexibility but lower strength.

Steel Core (IWRC or IWS)-Made of steel strands; offers greater strength, rigidity, and heat resistance, ideal for heavy loads.

2. Understanding Wire Rope Marking Codes

Each wire rope is identified by a specific marking code, which describes its structure, strand count, core type, and other properties.

Understanding these markings allows engineers and technicians to select the right wire rope for their intended application with precision and safety.

For example:

6×19S+FC → Six strands, each with 19 wires (Seale construction) with a fiber core.

6×19S+IWRC → Same structure but with an independent wire rope core.

These codes help differentiate ropes based on performance characteristics like flexibility, tensile strength, and fatigue resistance.

3. Common Types of Wire Ropes

Below are some of the most frequently used wire rope constructions in industrial and elevator applications:

3.1. 6×7 Series Round Strand Wire Rope

Structure: Six strands, each containing seven wires.

Variants:

6×7+FC-Fiber core for better flexibility.

6×7+IWS-Steel strand core for higher strength.

Variant Type: 6×9W (Warrington Type), available in both 6×9W+FC and 6×9W+IWR versions.

This type is widely used in light-duty hoisting and traction equipment.

3.2. 6×19(A) Series Round Strand Wire Rope

Structure: Six strands, each with 19 wires in a Seale pattern.

Variants:

6×19S+FC-Fiber core version.

6×19S+IWR-Steel wire rope core version.

Also available in Warrington pattern (6×19W), offering both fiber and steel core options.

This series offers an excellent balance between flexibility and strength, making it ideal for elevator wire ropes and general.