Wire rope to sheave ratio is?

Wire rope to sheave ratio is?

• A. 25 to 1
• B. 15 to 1
• C. 30 to 1
• D. 20 to 1

Answer: (D)

The important idea is that the rope must bend smoothly over the sheave. If the sheave is too small relative to the rope, the bend is tight, which increases bending stress, causes faster wear, and shortens rope life. The standard guideline is a minimum sheave diameter about 20 times the rope diameter, so the rope-to-sheave ratio is 20 to 1. This larger bend radius reduces contact stress on both the rope and the groove. For example, a rope 1 inch in diameter should use a sheave at least 20 inches in diameter. Smaller ratios (like 15:1) would produce sharper bends and more wear, while larger ratios (25:1, 30:1) are acceptable but simply exceed the minimum requirement.

The important idea is that the rope must bend smoothly over the sheave. If the sheave is too small relative to the rope, the bend is tight, which increases bending stress, causes faster wear, and shortens rope life. The standard guideline is a minimum sheave diameter about 20 times the rope diameter, so the rope-to-sheave ratio is 20 to 1. This larger bend radius reduces contact stress on both the rope and the groove. For example, a rope 1 inch in diameter should use a sheave at least 20 inches in diameter. Smaller ratios (like 15:1) would produce sharper bends and more wear, while larger ratios (25:1, 30:1) are acceptable but simply exceed the minimum requirement.