Tool size preference?

• A. Larger
• B. Smaller
• C. Same
• D. Variable

Answer: (A)

Tool size affects rigidity and how much the tool deflects under cutting forces. A larger diameter tool is stiffer (deflection is lower for the same load), so it resists bending and vibration better. That reduced deflection translates to more accurate dimensions and a smoother surface finish, and it also supports higher material-removal rates because you can take heavier cuts without sacrificing accuracy. So, when geometry and clearance permit, a larger tool diameter is preferred. A smaller tool would deflect more and chatter more easily, a same-sized tool wouldn’t gain the stiffness advantage, and a variable size isn’t necessary if a larger diameter fits the job.