The throat opening of a crane hook must not exceed what percentage of its original size?

The throat opening of a crane hook is a critical component that is designed to handle loads safely. When considering the percentage of allowable wear or deformation, it is important to maintain the structural integrity and operational safety of the hook.

If the throat opening exceeds 15% of its original size, it could significantly compromise the hook's strength and increase the risk of failure under load. This percentage is established based on safety standards and engineering principles that ensure the crane hook remains effective and reliable during operation. Reducing the size of the throat opening increases the risk of slippage and accidents, making it essential to adhere to the maximum threshold to maintain safety regulations.

The percentages associated with the other options are either too high, which could allow dangerous levels of wear, or too low, which may not represent the practical limits recognized by industry standards. Thus, the correct threshold for the throat opening of a crane hook is capped at 15% to ensure safe lifting operations.