CNC Milling ABS Plastic

For prototypes and small batches, milling saves the mold cost and the weeks spent making the mold. A design change means updating the CAD file instead of reworking a tool. Once the volume is high enough to pay back a mold, injection molding gives a lower cost per part.

Many projects use both. Parts are milled first to test fit and function, then moved to a mold once the design is settled.

On stable features in rigid materials such as POM and PEEK we regularly hold ±0.01 mm. Plastic moves more than metal. Nylon absorbs moisture and can change size. PC and PMMA often carry residual stress that appears after machining. Temperature swings also affect plastic more than aluminum or steel.

For tight fits we discuss the actual fit requirement, material choice, and how the part will be measured and stored. Tell us the fit you need and we will advise on the material and the tolerance.

How to choose

Housings and prototypes: ABS is the usual starting point.
Gears, bushings and wear parts: POM.
Clear covers and lenses: PMMA for clarity, PC when impact resistance matters more.
Moving parts under load: nylon.
Heat and chemical exposure: PEEK. It can run at around 250 °C in continuous service.

If you are not sure, send the part geometry and the real working conditions (temperature, load, chemicals, humidity). We will recommend a material with the quote.

Typical applications we see: medical device housings and internal components, automotive interior and under-hood plastic parts, electrical enclosures, consumer product prototypes, and industrial equipment covers or wear parts. The photos above are actual parts we have machined.

CNC machined medical device part

CNC machined industrial equipment part

CNC machined robotics part

PMMA light cover

CNC machined communications part

We also machine metal parts. See an example of custom aluminum milling.

Polishing: smoother surface and better appearance.
Bead blasting: even matte surface with a soft feel.
Painting and coating: color, wear resistance and a finished look.
Screen printing and laser engraving: text, markings and logos.

For optical faces on PMMA or PC, tell us which surfaces must stay clear so we can protect them during machining and polishing. Tell us the finish when you send the file, so the quote and the lead time cover it.

Send your STEP, IGS or STL file, or a 2D drawing, together with the material and quantity.

We review the part and reply within 24 hours with a quote and DFM feedback.

After you confirm, we machine the parts.

We apply the finish you chose, then pack the parts. Assembly and functional testing are available on request.

Prototypes usually ship 3–7 working days after you confirm the drawing and material. Larger quantities get a firm date with the quote.

Add a radius to inside corners. The cutter is round, so a perfectly sharp inside corner cannot be milled.

Avoid very thin walls and tall thin ribs. Plastic is soft and flexes under the cutter, which hurts accuracy.

Mark the features that really need tight tolerances and leave the rest general. It keeps cost down and helps us choose a stable machining sequence.

For nylon, tell us if the part works in a humid environment. Moisture changes its size.

For clear PMMA or PC parts, tell us which faces must be optically clear so we can plan the finish.

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