Which wrench is best suited for the final tightening of a nut?

• A. Open-end wrench
• B. Box-end wrench
• C. Adjustable wrench
• D. Socket wrench

Answer: (B)

When you’re finishing a nut, you need a tool that grips securely so you can apply the last bit of torque without slipping. A box-end wrench surrounds the nut with a closed ring, giving full contact on all sides. This even contact distributes the load, prevents slipping, and reduces the risk of rounding the corners as you approach the final torque. Open-end wrenches contact only two sides, making slippage and rounding more likely under high torque. An adjustable wrench can slip or deform under pressure, which undermines precision in the final tightening. A socket wrench provides strong grip and high torque as well, but in close or awkward spaces the box-end’s complete enclosure gives the most reliable, slip-free control for final tightening.