How should the manufacturer's rated load capacity be adjusted to determine the safe working load of an anchor?

• A. Divided by two
• B. Divided by four
• C. Divided by three
• D. Subtracted by one

Answer: (B)

Applying a safety factor to the manufacturer's rated capacity to determine the safe working load is the principle here. The rating given by the manufacturer assumes ideal conditions, so to account for real-world factors like dynamic (shock) loading, angle of pull, wear, and imperfect anchors, we reduce that rating. Using four as the divisor provides a conservative margin, ensuring the working load stays well within what the setup can safely handle. For example, a 10,000 lb rating becomes a 2,500 lb safe working load. Dividing by two or three would yield a larger safe load and offer less margin, while subtracting a fixed amount doesn’t scale with the load. That’s why dividing by four is the correct approach.