Machine tool

A powered mechanical device, typically used to fabricate metal components of machines by the selective removal of metal.

Examples of machine tools are:

• lathe (work rotates, single-edge cutter is fixed)
• mill (work is fixed, multi-edge cutter rotates)
• drill (like mill, but optimized to make holes)
• surface grinder[?]
• broach[?]
• gear shaper[?]
• shaper[?]
• Stewart Platform[?] mills

Machine tools can be operated manually, or under automatic control. When operated directly by computers, they are referred to as CNC[?] for computer numerical control[?] machine tools.

When fabricating or shaping parts, several techniques are used to remove unwanted metal. Among these are:

• single edge cutting tools
• multiple edge cutting tools
• grinding
• EDM (electrical discharge machining)

Several regions of the United States became centers for machine tool development, including Cincinatti[?], Ohio and Springfield, Vermont.