Use practical walls, radii and features
Thin walls can move under clamping and heat. Add internal radii, avoid deep narrow pockets and keep hole-to-edge distances suitable for the material.
Prepare a better machining drawing
Design Guide for CNC Machined Plastic Parts
Plastic parts expand, flex, absorb heat and carry internal stress differently from metal. A machining drawing should protect the features that matter without forcing unnecessary tolerance and cost across the entire part.
PrioritizeCritical interfaces and datums
AvoidUniversal metal tolerances
ConfirmMaterial, conditioning and inspection
Project logic
Make the process fit the product.
Dimension from functional datums
Identify the mounting face, mating features and critical hole patterns. Do not over-dimension the part from several competing origins.
State inspection conditions
Plastic dimensions can change with temperature and moisture. Define any conditioning, measurement temperature and functional gauges required for acceptance.
Applications
Where this route creates value.
01Prototype components
02Gears and wear parts
03Fixtures and manifolds
04Transparent machined parts
Common questions
Details buyers ask before an RFQ.
Can plastic parts hold tight tolerances?+
Yes on selected features, but material stability, size, temperature and geometry influence what is practical. Apply tight tolerances only where function needs them.
Are threaded holes possible in plastic?+
Yes, but thread form, wall thickness, load and assembly cycles should be reviewed. Inserts may be better for repeated use.
Why did a flat plastic part warp after machining?+
Internal material stress and unbalanced stock removal can release distortion. Material conditioning and machining sequence help control it.