Wire Rope Technical Information | MSC Industrial Supply Co.

Wire Rope: Is composed of wire twisted into strands around a core. The basic unit is the wire. Strands consist of a number of individual wires laid about a central wire.
Wire rope consists of a group of strands laid helically around a core, or center.

Classifications

In a numerical classification of wire rope construction, the first number is the number of strands; the second number is the number of wires per strand. Thus, 6 x 7 means six strands of seven wires per strand.
The standard construction of wire rope falls into the following five general classifications: 6 x 7, 6 x 19, 6 x 37, 7 x 19 and 8 x 19:

7 x 19 Class Wire Rope: 7 Strands, Nominally 19 Wires Per Strand: Use when flexibility and fatigue are concerns. Common applications include running rigging on sailboats, exercise equipment, winches and garage doors.

8 x 19 Class Wire Rope: 8 Strands, Nominally 19 Wires Per Strand: Use where a minimum rotation or spinning is highly desirable. Common applications include lifting or lowering of free loads with a single line.

6 x 7 Class Wire Rope: 6 Strands, 7 Wires Per Strand: Use where ropes are dragged over the ground or over rollers and resistance to wear and abrasion are important factors. The wires are quite large and stand a great deal of wear. The 6 x 7 is a stiff rope and needs sheaves and drums of large size. It will not stand bending stresses as well as ropes with a large number of wires.

6 x 19 Class Wire Rope: 6 Strands, Nominally 19 Wires Per Strand: Widely used and found in many variations throughout nearly all industries. With its combination of flexibility and wear resistance, rope in this class can be suited to the specific needs of diverse kinds of machinery and equipment. The designation 6 x 19 is only nominal as the number of wires per strand ranges from 15 to 26.

6 x 37 Class Wire Rope: 6 Strands, Nominally 37 Wires Per Strand: Characterized by the relatively large number of wires used in each strand. Ropes of this class are among the most flexible available, but their resistance to abrasion is less than the 6 x 19 class. The designation of the 6 x 37 is again only nominal as in the 6 x 19 class.

Types

Fiber Core: Wire rope with a synthetic or natural fiber cord of rope as a core to hold or position other strands. Fiber core adds flexibility without adding strength to the wire rope. If the operating environment exceeds 180°F, a steel-cored rope should be used.

IWRC (Independent Wire Rope Core): A wire rope used as the axial member of a larger wire rope. IWRC has a higher strength than fiber core or strand core. It is not as flexible as fiber core, but more flexible than strand core. Provides better crush resistance than fiber core.

Strand Core: Wire rope with a wire strand core used as the core of the wire rope. It has higher strength than fiber core and less flexibility than fiber core or IWRC.