WIRE ROPE
Construction of wire rope
The design of wire rope is determined by A) STRAND CONSTRUCTION - the number and arrangement of wires in each strand. B) ROPE CONSTRUCTION - the number and arrangement of strands in each rope C) THE CORE
Grades of Wire Rope - Tensile Strength
Cosmo Wire Ltd's wire rope and cable are made of steel wires classified into following tensile strength grads to meet various requirements according to the application.
| A) 165Kg/mm2 | 1570N/mm2 | PS |
| B) 180Kgs/mm2 | 1770N/mm2 | IPS |
| C) 200Kgs/mm2 | 1960N/mm2 | EIPS |
Lay of wire rope.
Right Lay
The rope is closing direction is Clockwise
Left Lay
The rope is closing direction to Counter clockwise
Regular Lay
Wires in strand are laid in the opposite direction of the strand and are parallel to the rope axis.
Lang Lay
Wires in the strand are laid in the same direction of the strand and are in an angle to the rope axis.
Cores for Wire Rope
Steel core
· IWRC : Independent Wire Rope Core - 7x7 construction
The core is an independent wire rope, usually using the construction is 7x7
· WSC : Wire Strand Core - 1x7, 1x19 construction
The core is an independent wire strand, normally having the same construction as the outer strands of rope.
Fiber Core
· Natural Fibers Core : Sisal, Hemp, Jute.
· Synthetic Fiber Core : Polyamide, Polyethylene, Polypropylene.
Preformed Wire Rope
In the preforming process, the wires and strands are given their finical pitch before being laid up into rope. Rope made in this way shows no tendency to untwist when cut.
Lubrication
Lubrication reduces internal friction of the wires and strands and protects the wire rope from the corrosion. Grease is applied to ropes and the type is :
| Type | Lube Material | Application | Appearance |
|---|---|---|---|
| DRY | Rust Prevent Oil | Very Light | No Grease |
| A-0 | Rust Prevent Oil & Petrolatum | Very Light Core A-1, Strand Dry | Core GreasedStrand dry |
| A-1 | Petrolatum | Light & Tightly Wiped | Lightly Greased |
| A-2 | Petrolatum | Loosely Wiped | Greased |
| A-3 | Petrolatum | Not Wiped | Heavy Greased |
| B | Petrolatum & Asphaltum | Medium DutyTightly Wiped | Dark color GreasedSlightly Wet |
| C | Asphaltum | Heavy DutyLoosely wiped | Black Color Greased Wet & Sticky |
| D | Asphaltum | Heavy DutyDouble Greased | Very black colorWet & Sticky |
Diameter of wire rope
The diameter of wire rope is the diameter of the circle which encloses all of wires. When measuring wire rope, it is important to take greatest distance of the outer limits of the crowns of two opposite strands. A measurement across the valleys will result in incorrect lower readings.
