Which of the following is a type of milling machine commonly used in shops?

• A. Knee and column mills
• B. Lathe
• C. Planer
• D. Gear hobbing machine

Answer: (A)

Milling machines remove material with a rotating cutter and let you shape parts by moving the workpiece and the cutter in multiple directions. Knee and column mills are a common type found in shops because they combine a knee that supports the worktable with a column that carries the spindle head, giving flexible three-axis movement and easy setup for a wide range of milling operations. The table moves in two directions while the spindle can move up and down, allowing precise cuts, slots, pockets, and contours on various materials.

In contrast, a lathe mainly performs turning around a rotating workpiece, not milling; a planer is used for very large, flat surfaces with a stationary cutter; and a gear hobbing machine is specialized for cutting gears. So the knee and column mill best fits as a type of milling machine commonly used in shops.