Wire Rope Construction, Finish & Grade

Wire Rope Construction

Wire rope is identified by its construction, or the number of strands per rope, and number of wires in each strand. For example, the construction 6x25 denotes a 6-strand rope, with each strand having 25 wires. Constructions having similar weights and breaking strengths are grouped into wire rope classifications, such as the 6x19 and 6x37 Classes.

Wire Rope Finish

The term bright refers to a wire rope manufactured with no protective coating or finish other than lubricant. Some applications do require more corrosion protection than lubricant can provide. In these instances, a galvanized finish is provided. Contact Assembly Specialty for more information on galvanized wire rope.

Wire Grade

Improved plow (IPS) steel is strong, tough, durable steel that combines great strength with high resistance to fatigue. Its minimum tensile strength varies from 223 to 258 ksi, depending upon wire diameter. Extra Improved Plow (EIP) steel has a minimum tensile strength that varies from 245 to 284 ksi, depending upon wire diameter. Extra Extra Improved Plow (EEIP) steel, is a grade used where a high breaking strength is required. This grade typically provides a breaking strength a minimum of 10% higher than (EIP) and is found primarily as a standard grade for specialized wire rope and often is available for standard wire ropes upon request. Developed for the federal government, Royal Purple Plus is Wirerope Works’ highest strength grade available to Bethlehem Wire Rope customers. Royal Purple Plus provides a breaking strength 35% higher than Purple Plus, and is available in Wirerope Works’ Triple-Pac hoist rope. It is the grade of wire which determines the nominal breaking strength for each diameter and construction. Note the acceptance strength listed in the various tables for wire rope products is 2-1/2% below the nominal strengths listed. Other grades are available to meet specific requirements. Some grades are covered by wire rope standards while others may be specially tailored. Contact Assembly Specialty for more information.