CNC Machining of Delrin (POM)
Delrin (POM) is stiff, low-friction and dimensionally stable, which is why it shows up in gears, bushings and precision mechanisms that run without lubrication.
Why it is hard to machine
POM cuts cleanly but moves: it has a comparatively high thermal expansion and relaxes under sustained clamping, so a part that gauges good hot can shrink or warp once it cools and settles.
Process controls that matter
Thermal expansion
POM grows and shrinks noticeably with temperature. Machining temperature and measurement temperature both matter.
Clamping relaxation
Sustained pressure deforms POM over time. Low-force workholding and stress-aware sequencing hold size.
Burrs and fuzzing
POM fuzzes at edges if cut too slowly. Correct speeds plus controlled deburring leave crisp edges.
Tolerances, inspection and documentation
Typical applications
Gears and racks, bushings and bearing seats, precision slides, insulators, fluid-handling and instrument components.