Definition
A machining method that removes material with a rotating cutter, contributing to consistency of mechanical parts and the machining of complex surfaces.
Milling removes material with a rotating cutter and should be discussed separately from turning, which typically rotates the workpiece. Its development involved accumulated advances in cutters, machine tools, workholding and feed control, and cannot be reduced to a single person's moment of invention.
The U.S. National Park Service describes specialized cutting machinery developed by Hall in the early 19th century for interchangeable firearms manufacture, treating some linear cutting machines as precursors of later milling machines. This material supports a link between machining equipment and interchangeable manufacture, but is insufficient to establish that all early machines were equivalent to modern general-purpose milling machines.
Records of machine manufacturing in late Qing China require a specific distinction between lathes and milling machines. This review has not used the date when Chinese-made lathes appeared as a substitute for the date when milling was adopted in China.
Principles and impact
Problems solved
- Made the machining of certain surfaces and part shapes more consistent and repeatable.
Principles
- Relative motion between a rotating cutter and the workpiece removes material.
Improvements
- Specialized cutting equipment helped produce more consistent, repeatable part shapes.
Significance
- Provided an important method for machining mechanical parts and controlling consistency.
History and applications
People
John H. Hall
Organizations
Harpers Ferry Armory
Events
Hall developed specialized cutting machinery in the early 19th century
Applications
Surface machining of mechanical parts
Limitations
- The presence of a machine does not automatically guarantee interchangeable parts; positioning, measurement and process control are also required.
Upstream and downstream relations
Upstream
No direct upstream relations recorded
Downstream
Sources: John H. Hall