Cable Diameter Related to Pulley or Sheave Diameter
The service life of cable and wire rope can be increased if (1) it operates over the largest possible pulley or sheave diameter, and (2) it is properly supported in the pulley or sheave groove. The working life of the individual wire strands is greatly reduced as the pulley or sheave diameter is diminished. The chart below shows minimum tread diameters over which various sizes and constructions of cable should operate.
Minimum Tread Diameter for Pulleys or Sheaves
RATIO OF CABLE DIAMETER TO PULLEY DIAMETER
| Desirable Minimum | Critical Minimum | |||||||
| 42:1 | 24:1 | 12:1 | 28:1 | 18:1 | 10:1 | |||
| Cable Diameter in Inches | 6×7 or 7×7 | 6×19 or 7×19 | 6×31 7×31 6×37 | 6×7 or 7×7 | 6×19 or 7×19 | 6×31 7×31 6×37 | ||
| 1/16 | 2-5/8 | —- | —- | 1-3/4 | —- | —- | ||
| 3/32 | 3-15/16 | 2-1/4 | —- | 2-5/8 | 1-11/16 | —- | ||
| 1/8 | 5-1/4 | 3 | —- | 3-1/2 | 2-1/4 | —- | ||
| 5/32 | 6-9/16 | 3-3/4 | —- | 4-3/8 | 2-7/8 | —- | ||
| 3/16 | 7-7/8 | 4-1/2 | —- | 5-1/4 | 3-3/8 | —- | ||
| 7/32 | 9-13/16 | 5-1/4 | —- | 6-1/8 | 4 | —- | ||
| 1/4 | 10-1/2 | 6 | 3 | 7 | 4-1/2 | 2-1/2 | ||
| 5/16 | 13-1/8 | 7-1/2 | 3-3/4 | 8-3/4 | 5-5/8 | 3-1/8 | ||
| 3/8 | 15-3/4 | 9 | 4-1/2 | 10-1/2 | 6-3/4 | 3-3/4 | ||
| 7/16 | 18-3/8 | 10-1/2 | 5-1/4 | 12-1/4 | 7-7/8 | 4-3/8 | ||
| 1/2 | 21 | 12 | 6 | 14 | 9 | 5 | ||