PL · engineering plastic
Polyamide Nylon 6/6 (unfilled and 30% GF)
Machines well when dry, but it absorbs moisture from the air and grows - which is the opposite of what most machined parts are expected to do.
Quoting this material
- Typical lead time
- 7–14 working days
- Condition
- Extruded stock, dried and sealed; moisture-conditioned after machining where the part needs toughness
- Achievable finish
- Ra 1.6 µm typical · Ra 0.8 µm best
Machined in-house to your drawing: see the precision CNC machining service and the machine and inspection capability it runs on.
Machinability
Our own 1–10 shop ranking, not a published index: 10 is free-cutting brass C360, 1 is Inconel 718. It ranks how a material behaves on the floor - cycle time, chip control and tool life together. Where a published index exists it is quoted in the note.
Machines well when dry, but it absorbs moisture from the air and grows - which is the opposite of what most machined parts are expected to do.
Properties as supplied
| Parameter | Value | Unit |
|---|---|---|
| Tensile strength | 80 | MPa |
| Modulus of elasticity | 3.0 | GPa |
| Hardness | 80 | Shore D |
| Continuous service temperature | 105 | °C |
| Thermal conductivity | 0.25 | W/m·K |
| Density | 1.14 | g/cm³ |
Hardness, tensile and thermal figures are typical published values for the condition stated. Actual mill certificates govern; send the specification with the drawing and we confirm against the certificate before the material is cut.
Condition
Extruded stock, dried and sealed; moisture-conditioned after machining where the part needs toughness
Heat treatment
No heat treatment in the metal sense. What matters is moisture: dry nylon machines to a clean finish but is brittle, and a part that absorbs moisture afterwards grows by around 1–2% for unfilled grades. Moisture conditioning is a controlled step where a part has to be tough in service.
Achievable surface finish
Ra 1.6 µm
Ra 0.8 µm
Dry nylon machines to a good finish; moisture-conditioned nylon cuts more like a soft, stringy plastic.
Tooling and cutting parameters
Cutting speed
- 200–500 m/min (sharp uncoated carbide)
Feed
- 0.10–0.30 mm/rev turning · 0.10–0.25 mm/tooth milling
Tooling
- Sharp uncoated carbide; the glass-filled grade needs diamond coating
Coolant
- Air or mist; keep flood coolant off it, the material absorbs water
Starting points for carbide on a rigid setup, not a guarantee. The right numbers depend on the machine, the toolholder and the fixturing - ask and we will say what we would actually run.
Typical applications
- Gears and wear components
- Rollers and guide wheels
- Bushes and bearing cages
- Electrical connectors and housings
- Textile and conveyor machinery parts
DFM notes for this grade
- Moisture absorption is the design constraint: an unfilled nylon part can grow 1–2% between dry and conditioned, which is more than any tolerance worth quoting on a 100 mm part
- Where the part must be both tough and dimensionally stable, the glass-filled grade is the answer - it absorbs far less and holds its size
- Do not use flood coolant on nylon: water absorption during machining makes the part move after the event
Questions buyers ask
- Why does my nylon part fit differently a week after machining?
- Because it absorbed water from the air. Unfilled nylon 6/6 takes up around 2.5% moisture at equilibrium in normal humidity, and that changes the dimensions - usually by more than the tolerance. If the fit matters, specify a glass-filled grade or condition the parts and measure them wet.
- Is nylon a good gear material?
- Excellent for low-load, quiet-running gears and it is often better than metal because it damps noise and tolerates small misalignments. The limits are temperature around 100 °C and moisture, both of which change the tooth geometry.
Grades we would quote instead
POM-C (Acetal Copolymer)
8/10The best-machining plastic in this catalogue: it produces clean chips, holds a tolerance without drama and takes a fine finish.
PEEK
5/10Machines cleanly for a plastic but it holds heat at the cut and the swarf will not break.
UHMW-PE
6/10Cuts easily but badly: it is soft, it moves under clamping and it produces a continuous string of swarf that has to be managed.