Hook Strain is calculated to verify that the SWL of the ____ is not exceeded.

• A. rope
• B. block
• C. fiber
• D. spool

Answer: (B)

Hook strain measures the tension in the hook, which is the connection point to the load and part of the block assembly. The Safe Working Load (SWL) of the system is determined by the block’s rating, since the hook and the block must carry the load safely. By calculating hook strain, you’re checking that the load transmitted through the lifting setup does not exceed the block’s rated capacity. Rope, fiber, or other components have their own ratings, but hook strain specifically targets the block’s SWL.