The 'Rule of thumb' minimum for wire rope to sheave ratio is

The 'Rule of thumb' minimum for wire rope to sheave ratio is

• A. 10:1
• B. 15:1
• C. 20:1
• D. 25:1

Answer: (C)

When wire rope bends around a sheave, the tighter the bend, the higher the bending stress and contact pressure on the rope. A practical guideline to keep rope life and performance reasonable is a 20-to-1 ratio: the sheave diameter should be about twenty times the rope diameter. This larger bend radius reduces stress on the rope strands, minimizes wear in the grooves, and helps the rope track smoothly in the sheave, which together extend rope service life and improve safety. Using smaller ratios would mean tighter bends, more wear, and faster degradation of the rope. In real-world use, manufacturers may specify larger diameters for specific rope constructions or service conditions, but 20:1 is the standard rule of thumb.

When wire rope bends around a sheave, the tighter the bend, the higher the bending stress and contact pressure on the rope. A practical guideline to keep rope life and performance reasonable is a 20-to-1 ratio: the sheave diameter should be about twenty times the rope diameter. This larger bend radius reduces stress on the rope strands, minimizes wear in the grooves, and helps the rope track smoothly in the sheave, which together extend rope service life and improve safety. Using smaller ratios would mean tighter bends, more wear, and faster degradation of the rope. In real-world use, manufacturers may specify larger diameters for specific rope constructions or service conditions, but 20:1 is the standard rule of thumb.