Part block
Machined seals, bushings and wear parts
Not every seal is moulded. Below a few thousand pieces, or when the geometry is a one-off repair part, machining PTFE, PEEK, POM or nylon is the cheaper route — and it is the one that holds a tolerance without a tool.
What we make in this block
| Diameter range | Ø3 mm – Ø300 mm turned; rings and pads up to 400 mm milled |
|---|---|
| Tolerance | ±0.02 mm on plastics (they move more than metal); ±0.05 mm on filled PTFE |
| Thickness | 0.5 mm – 50 mm |
| Materials | PTFE (virgin and glass/carbon filled), PEEK, POM (acetal), nylon PA6 / PA66, UHMW-PE, PPS, Vespel-type polyimide |
| Service temperature | POM to 90 °C, nylon to 100 °C, PEEK to 250 °C, PTFE to 260 °C |
| Typical parts | Seal rings, backup rings, bushings, wear pads, guides, insulators, rollers, gaskets |
| Finishes | None by default; annealing for PEEK and POM to relieve stress; laser marking on request |
Plastic by application — the trade-off that usually decides it
| Material | Friction | Temperature | Wear | Cost |
|---|---|---|---|---|
| PTFE (virgin) | Lowest | 260 °C | Soft, cold-flows | Medium |
| PTFE (glass filled) | Low | 260 °C | Better creep resistance | Medium-high |
| PEEK | Low-medium | 250 °C | Excellent | High |
| POM | Low | 90 °C | Good | Low |
| Nylon PA6 | Medium | 100 °C | Good, absorbs moisture | Low |
| UHMW-PE | Very low | 80 °C | Excellent abrasion | Low |
Processes, materials and finishes
Processes
- CNC turning
- CNC milling
- Waterjet cutting (thin sheet)
- Annealing
- Deburring
Materials
- PTFE virgin / glass filled / carbon filled
- PEEK
- POM (acetal)
- Nylon PA6 / PA66
- UHMW-PE
- PPS
- Polyimide
Finishes
- None (as machined)
- Annealing
- Laser marking
How it is quoted
| Minimum order | 100 pieces per part number (prototype quantities from 1) |
|---|---|
| Sample lead time | 7–10 days after drawing approval |
| Production lead time | 25–35 days after sample approval |
| Quote turnaround | Within 24 hours, with DFM feedback |
Specific part pages in this block
Technical reading for this block
- CNC turning design rules
- Material selection guide
- Fits and tolerances (H7/h6)
- Part weight calculator
- Cost reduction checklist
Questions
When is machining a seal cheaper than moulding it?
Below roughly 2,000–5,000 pieces, depending on the geometry. A mould costs several thousand dollars and takes weeks; machining a PTFE ring costs a setup and a bar. Above that volume the mould wins.
Why do plastic parts measure wrong after machining?
Because the material moves after the cut. Plastics release internal stress when material is removed, so a ring machined to size can close up overnight. The fix is stress-relieved stock, annealing before the finish pass, or a stabilising allowance.
Can you hold H7 in POM or PTFE?
In POM yes, with care. In virgin PTFE it is not meaningful — the material cold-flows under load, so the bore changes in service. Filled PTFE or a PEEK bushing is the answer when the tolerance matters.
Do you supply food-contact or medical grades?
We machine the grade the drawing names, and the material certificate ships with the order. Whether a grade is suitable for food contact or medical use is a property of that grade and its certification, which the brand holds.
Send the drawing for seals and wear parts
Quotes come back within 24 hours with DFM feedback. Minimum order 100 pieces per part number; samples from one piece.