The fill factor of steel wire rope is typically defined as the ratio of the metallic cross-sectional area of the rope to the circular area corresponding to its nominal diameter. It reflects the proportion of the total space within the steel wire rope occupied by steel.
Common steel wire ropes typically have fill factors ranging from 0.46 to 0.75. This means that steel accounts for approximately 46% to 75% of the rope's total volume.
Wire ropes with an independent wire rope core (IWRC) generally have higher fill factors than those with a fiber core (FC). For example, 6x25F-FC has a fill factor of 0.50, whereas 6x25F-IWRC has a fill factor of 0.58.
For fiber core (FC) ropes, the fill factor typically decreases as the number of outer strands increases. 6x25F-FC has a fill factor of 0.50, while an 8x25F-FCrope has a fill factor of only 0.445.
For steel core ropes, the fill factor typically increases as the number of outer strands increases. 6x25F-IWRC has a fill factor of 0.58, whereas an 8x25F-IWRC rope has a fill factor of 0.587.
Steel wire ropes made from compacted strands have higher fill factors than those made from non-compacted strands. The fill factor can be further increased by subjecting the wire rope itself to compaction or rotary swaging processes.
A higher fill factor implies a higher minimum breaking force for the steel wire rope, though its flexibility is relatively reduced.
