Workpieces

Workpiece refers to the piece of material that is subjected to a manufacturing operation. In machining, a workpiece is the item clamped in a vise or fixture and processed by tools such as drills, mills, lathes, or grinders. The term applies across metalworking, woodworking, plastics, and composites, and can denote raw stock, semi-finished parts, or finished components awaiting further steps.

Key characteristics include material type (metals, polymers, ceramics, composites), geometric shape and size, required tolerances and surface finish, and any heat treatment or coatings applied prior to or after processing. The selection of a workpiece must consider machinability, hardness, and distortion tendencies to determine appropriate tooling and processes.

Common operations on a workpiece involve material removal, such as turning, milling, drilling, or grinding; forming or stamping; joining or assembly steps that modify the piece; and additive processes that build on the base stock. Workholding devices—vices, chucks, clamps, and pallets—are critical for stability, accuracy, and safety during processing.

Quality control plays a central role: after processing, the workpiece is measured against dimensional specifications using gauging, metrology, and surface inspection to verify tolerances, straightness, roundness, and finish. Variations may lead to rejects, rework, or process adjustments.

In practice, workpieces are categorized by their stage (raw stock, semi-finished, finished) and by the operation performed (roughing vs finishing). They are fundamental units in manufacturing workflows, design, and assembly.