Polyetheretherketone cuts clean only when the blank is annealed, the tooling is sharp and the feeds are slow. We machine unfilled and filled grades to ±0.005 mm, from one prototype to 10,000+ parts.
If any of these look familiar, the fix is usually in the blank, the tool or the clamping.
Stock that was not annealed before cutting keeps moving for days after the last pass. A bushing that measured Ø20.00 mm on the bench can drift out of round once it sits in a warm assembly. Stress relief before machining is the only reliable cure.
PEEK is notch sensitive. A dull end mill or too much feed leaves micro cracks along a sealing lip, and those cracks open under pressure. Sharp carbide, climb milling and light finishing passes keep the edge intact.
Glass and carbon fibres abrade carbide fast. We see shops burn through a cutter per part and still miss the bore tolerance. The answer is coated tooling, shorter tool life windows and a planned re-cut before the edge breaks down.
Heat builds at the cutting edge because PEEK conducts heat poorly. Run it too fast and the surface smears, turns brown and loses dielectric strength. Coolant, modest spindle speed and sharp geometry protect both finish and electrical performance.
Three process steps decide whether the part holds size after it leaves the machine.
Extruded PEEK rod and plate carry locked-in stress from the mill. Cut into it cold and the part relieves that stress by moving. We anneal blanks to the supplier's recommended cycle before the first cut, then rough, rest and finish.
For thin-wall bushings and long insulators we rough within 0.5 mm, let the part cool fully, then take the finishing pass. It costs one extra setup and removes most of the post-machining drift.
Polyetheretherketone machines more like a soft metal than a typical plastic. It wants positive rake, polished flutes and high surface speed with a modest chip load. Get that wrong and you get smeared walls and pulled fibres on filled grades.
We keep a separate tool set for filled material so abrasive wear never carries over to an unfilled job. Every finishing cutter is checked for edge condition before the last pass, not after the part is off the table.
Match the grade to the load, the temperature and the wear mode before you finalise the print.
| Grade | Best For | Watch Out For |
|---|---|---|
| Unfilled PEEK | Seals, insulators, food-contact parts | Low wear resistance under sliding load |
| PEEK GF30 | Bushings, structural brackets, pump parts | Abrasive to tooling, harder to hold a fine finish |
| PEEK CF30 | High-stiffness wear parts, bearings | Conductive, so not for electrical isolation |
| PEEK with PTFE / graphite | Dry-running bearings and seals | Lower mechanical strength than the base grade |
| Medical-grade PEEK | Implant and instrument components | Needs traceable stock and clean handling |
| PEEK stock shapes | Rod, plate and tube from 6 mm up | Extruded stock must be annealed before cutting |
Most PEEK programs need more than one operation. We keep them under one roof.
Complex PEEK geometry in one setup. Angled ports, contoured seal grooves and undercut features without repositioning errors.
Mill-turn for bushings, sleeves and threaded insulators. Turning holds concentricity on thin-wall tubes far better than milling alone.
One-off PEEK parts for fit checks and test rigs. Same process as production, so the prototype predicts the final part.
Bead blasting, tumbling and polishing. We avoid processes that add heat or solvents to a PEEK surface.
The metal housing, bracket or shield that goes around your plastic part. One supplier, one tolerance stack.
For jigs, fixtures and low-load prototypes where PEEK machining would be overkill on cost.
Numbers you can check a print against.
| Item | Range |
|---|---|
| General tolerance | ±0.005 mm (±0.0002 in) |
| Fine finish | Ra 0.2–0.8 μm |
| Standard machined finish | Ra 0.8–1.6 μm |
| Maximum part size | 4,000 mm |
| Large travel | 4,000 × 400 × 150 mm |
| Rotary table | Ø400 mm |
| Inspection | 100% before shipment, reports on request |
| Order size | One prototype to 10,000+ parts, no MOQ |
The same tolerance we quote for aluminium applies to PEEK, provided the blank is annealed and the finishing pass is light.
Angled seal grooves and contoured ports come off one setup, which removes the re-datum error that shows up on multi-setup plastic parts.
We review wall thickness, corner radii and thread depth against the grade you picked, and flag the features that will not hold before cutting starts.
PEEK, POM, PA, PC and filled grades. The shop knows which materials need a cooling pause and which need a sharper cutter.
Raw material check, in-process monitoring and final inspection on every run. Dimensional reports are available when your drawing calls for them.
One prototype for a test rig, or a 10,000-part production run. Nothing in the process changes between the two.
Bushings and wear pads that must hold size across a wide temperature swing.
Insulators and instrument parts needing clean surfaces and traceable stock.
Low-friction bearing cages and joint liners that run without external lubrication.
Dielectric spacers and connector bodies where discolouration means a failed part.
We quote ±0.005 mm on features that are stable, meaning a wall thick enough to resist deflection and a blank that was annealed before cutting. Thin-wall tubes and long slender parts are harder and we will tell you which dimensions need a wider band.
If a print calls for a tolerance that will not survive the material's own movement, we raise it in the DFM review instead of shipping parts that drift in your incoming inspection.
Yes. GF30 and CF30 both cut cleanly, but the abrasive filler shortens tool life and changes the finishing strategy. We keep separate cutters for filled material so wear never transfers to an unfilled job.
Carbon-filled grades are electrically conductive. If the part is meant to insulate, stay with unfilled or glass-filled stock.
Almost always because the stock was not stress relieved. Extruded rod and plate carry internal stress, and removing material lets that stress pull the part out of shape over hours or days.
We anneal before roughing and leave a cooling pause between rough and finish. That is the step most shops skip when a quote looks unusually cheap.
For a dynamic seal face, Ra 0.2–0.8 μm is a reasonable target. Static seals are usually fine at Ra 0.8–1.6 μm. Anything rougher than Ra 3.2 μm will wear the mating seal faster.
Note that polishing PEEK adds heat and can smear the surface. We reach fine finishes with cutter geometry and light passes rather than heavy buffing.
Yes. There is no minimum order quantity. A one-piece run goes through the same annealing, tooling and inspection steps as a production batch.
That matters for PEEK because a prototype cut on a different process tells you very little about the production part.
Quotation and a free DFM analysis come back within 12 hours. Production can start within 24 hours of approval, and parts typically ship in 3–5 days.
Filled grades and medical-grade stock may need to be ordered in, so mention the grade early if the schedule is tight.
Uploads are secure and treated as confidential. We can sign an NDA before you send drawings if your program requires it.
We hold ISO 27001:2022 for information security, alongside ISO 9001:2015, IATF 16949:2016 and ISO 13485:2016.
Choose PEEK when the part sees continuous service above roughly 100 °C, needs chemical resistance to aggressive fluids, or has to keep its stiffness at temperature. POM is cheaper and machines faster for room-temperature wear parts.
If the load is light and the temperature is moderate, POM or PA will usually do the job at lower cost. We will say so if that is the case.
Upload the print and the grade. You get a quotation and a DFM analysis within 12 hours, and parts that pass inspection before they ship.
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Upload your 3D model or 2D drawing and get a quotation with a free DFM analysis. Maximum processing size 4,000 mm.
CNC Metals 13 grades
CNC Plastics 10 grades
Machines & processes 12 options
Surface & post-processing 10 options
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