Which equation correctly computes the working load limit from breaking strength and safety factor?

Which equation correctly computes the working load limit from breaking strength and safety factor?

• A. WLL equals Breaking Strength multiplied by Safety Factor
• B. WLL equals Breaking Strength divided by Safety Factor
• C. WLL equals Breaking Strength plus Safety Factor
• D. WLL equals Breaking Strength minus Safety Factor

Answer: (B)

The working load limit is a conservative, safe-use value derived from the device’s breaking strength by applying a margin for uncertainty. The safety factor is a unitless number that reduces the breaking strength to a value you should actually use in practice. Dividing the breaking strength by the safety factor gives that reduced, safer limit. For example, if the breaking strength is 100,000 pounds and the safety factor is 5, the working load limit would be 20,000 pounds. Multiplying would inflate the allowable load, while adding or subtracting doesn’t reflect the margin intended by the safety factor. So, WLL equals Breaking Strength divided by Safety Factor.

The working load limit is a conservative, safe-use value derived from the device’s breaking strength by applying a margin for uncertainty. The safety factor is a unitless number that reduces the breaking strength to a value you should actually use in practice. Dividing the breaking strength by the safety factor gives that reduced, safer limit. For example, if the breaking strength is 100,000 pounds and the safety factor is 5, the working load limit would be 20,000 pounds. Multiplying would inflate the allowable load, while adding or subtracting doesn’t reflect the margin intended by the safety factor. So, WLL equals Breaking Strength divided by Safety Factor.