COMPONENTS: Wire rope consists of three basic components.
1. Wires
2. Strands, formed by wires, laid helically around a core.
3. Core, or center.
MATERIAL: Steel grades in wide use today are IPS (improved plow steel) or EIPS (extra improved plow steel), sometimes also referred to as XIPS, XIP, EIP. Stainless steel grades 302/304 and 316 are most common.
CORE: Its function is to provide proper support for the strands under normal conditions. Three types of core (or center) are commonly used.
1. Fiber Core (F.C.), usually polypropylene, sometimes hemp (H.C.) and sisal.
2. Independent Wire Rope Core (IWRC)
3. Wire Strand Core (WSC)
IWRC and WSC are sometimes referred to as steel wire core or steel center.
CONSTRUCTION: Expressed in numbers of strands x number of wires. 6 x 25 indicates that the wire rope consists of 6 strands, which in turn have 25 individual wires. Constructions are grouped into classes: 6×7 Class: Containing 6 strands that are made up of 3 through 14 wires, of which no more than 9 are outside wires 6×19 Class: Containing 6 strands that are made up of 15 through 26 wires, of which no more than 12 are outside wires. 6 x 37 Class: Containing 6 strands that are made up of 27 through 49 wires, of which no more than 18 are outside wires. 8×19 Class: Containing 8 strands that are made up of 15 through 26 wires, of which no more than 12 are outside wires.
19×7 Class: Containing 19 strands, each of which is made up of 7 wires.
8×19 and 19×7 class wire ropes have rotation-resistant properties, excluding elevator ropes.
The construction listed above are just some of the more popular constructions.
Other common constructions:
7 x 7,7 x 19: Galvanized cable. Sometimes referred to as aircraft cable but not intended for aircraft use. 1×7,1×19: Strand 7x7x7, 7x7x19: Cable Laid
Many others exist, some for highly specialized applications only.
Note that any class denotes the nominal number of wires in each strand. The actual number of wires may be different. For example: 6×37 class wire most commonly may consist of 36 wires, or 31, or 41.