Steel Wire Ropes
Standard Steel wire rope consist of a number of wires which are wrapped together to form strands. These strands are then wrapped together to form the wire rope. The number of strands in the construction defines the rope along with the number of elements (wires) in these strands. E.g. a 7 x 7 rope would have seven strands containing 7 wires. For more complex constructions, especially for multistrand ropes then the number of elements for the major components are named.
For certain ropes the core strand forms an independent element and is not included in the strand count. For the above rope fitted with an Independent Wire Rope Core then it would be called and 6x7 IWRC. The core may be fibre construction.
Wire ropes are formed with helically wound wires forming strands which are helically wound together to form the rope.
When an axial load is applied the free end of the wire rope will rotate. The degree of rotation is dependent on the construction of the wire rope.
This rotation is a defined performance critieria for the wire rope design and is given by the manufacturer as degrees per lay.
Wire- the individual wire elements
Strand- individual component of construction formed by helically wrapping wires
Rope - The completed construction
Lay - The Pitch of the strands ( typically approximately 6.5 times rope diameter)