The lathe tool shown as figure "R" in the illustration would best be used to __________. GS-0090

Correct Answer: Option A — form a right-cut square shoulder

Figure R is a side-facing tool with a sharp, square-nose geometry, specifically engineered to cut into a corner and produce a clean, 90-degree square shoulder. Its design ensures that the tool can reach the corner without interference, providing a precise transition between the turned diameter and the face.