Machined Plastics
Machined plastic is plastic that is shaped by a machine, such as a lathe or drill, as opposed to being molded or extruded. Plastic machining uses CNC (Computer Numerical Control) machining to produce precision parts such as medical equipment, food processing equipment, valves, and automotive parts.
Two main considerations when deciding whether to extrude or machine plastic parts are volume and tolerance. Machining is used for smaller volumes or for plastic parts that require increased tolerances. While plastic created using molding or extrusion yields tolerances of about .004," machined plastics can have tolerances down to .001" depending on the type of plastic used. Plastic machining is also recommended for small volumes, general between 100 and 1,000, although it may sometimes also be suggested for orders of up to 5,000 pieces.
Some plastic machining services are registered with the FDA (Food and Drug Administration) or comply with military specifications (MIL-SPEC) or industry specific standards, such as AS 9000 and AS 9001 for aerospace and QS 9000 for domestic automobile manufacturing. These standards ensure high levels of quality and performance.