Shackles are sized by the diameter of steel in which section?

Shackles are specifically sized by the diameter of the steel in the bow section. The bow is the rounded part of the shackle that allows it to attach to various lifting devices, and it is critical for determining the shackle's load capacity and overall strength.

When selecting a shackle for lifting applications, understanding the size of the bow helps ensure that the shackle can withstand the intended load without failing. The bow's diameter is directly related to the amount of weight it can safely lift, as a larger bow generally indicates a higher load capacity.

The other sections, such as the front and back, do not provide the necessary information regarding the shackle's lifting capacity because they are not the primary load-bearing parts. The center of the shackle often refers to the pin or the connection point, which also does not determine the overall size criteria. Hence, concentrating on the bow diameter is crucial for proper rigging and safety practices.