Which accessory is used to raise a workpiece above the table for machining?

• A. Shims
• B. Parallels
• C. V-blocks
• D. Support rings

Answer: (B)

Parallels are the tool you use to lift a workpiece off the table in a controlled, level way. They’re precision blocks with flat, parallel faces that you stack or place under the workpiece (often in a vise or on a surface plate) to set the exact height you need. Because the faces stay true and flat, they keep the workpiece aligned with the cutting tool and the machine’s axes, which is essential for accurate machining and proper clamping clearance.

Shims are thin pieces used for fine leveling or taking up small gaps, not for providing a stable, repeatable height for general workholding. V-blocks are intended to support round stock by sitting in a V-shaped groove, not to raise an entire workpiece above the table. Support rings are suited for supporting cylindrical stock or pipe, not for elevating a rectangular workpiece for typical milling or drilling operations.