PL · engineering plastic
Polyetherimide PEI (Ultem 1000 / 2300)
A hard, stiff, amber-coloured plastic that machines like a tough wood: clean chips, crisp edges and good dimensional stability. Tool wear is real on the glass-filled grade.
Quoting this material
- Typical lead time
- 10–18 working days
- Condition
- Extruded rod and sheet, or moulded
- Achievable finish
- Ra 1.6 µm typical · Ra 0.4 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.
A hard, stiff, amber-coloured plastic that machines like a tough wood: clean chips, crisp edges and good dimensional stability. Tool wear is real on the glass-filled grade.
Properties as supplied
| Parameter | Value | Unit |
|---|---|---|
| Tensile strength | 105 | MPa |
| Modulus of elasticity | 3.2 | GPa |
| Hardness | 85 | Shore D |
| Continuous service temperature | 170 | °C |
| Thermal conductivity | 0.22 | W/m·K |
| Density | 1.27 | 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 rod and sheet, or moulded
Heat treatment
No heat treatment; the machined part is stable because the material has a high glass transition and low moisture uptake. Stress relieving is used on very close-tolerance parts.
Achievable surface finish
Ra 1.6 µm
Ra 0.4 µm
Machines to a clean, crisp edge with a good finish - one of the better plastics for a visible machined part.
Tooling and cutting parameters
Cutting speed
- 150–400 m/min (sharp uncoated carbide)
Feed
- 0.10–0.30 mm/rev turning · 0.10–0.25 mm/tooth milling
Tooling
- Sharp uncoated carbide; diamond-coated for the glass-filled grade
Coolant
- Air or mist
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
- Electrical and electronic insulators
- Medical trays and sterilisable hardware
- Aerospace interior and duct components
- Semiconductor handling fixtures
- High-temperature structural brackets
DFM notes for this grade
- It holds its dimensions far better than most high-temperature plastics, which is why it is used for a toleranced part in a hot environment
- Sterilisable and dimensionally stable under autoclave cycles - but the grade has to suit the sterilisation method, and steam against chemical sterilisation is a different selection
- The glass-filled grade is abrasive; specify diamond-coated tooling on a production run and expect the finish to depend on tool condition
Questions buyers ask
- PEI or PEEK for a high-temperature part?
- PEEK if the temperature is above about 170 °C or the chemical environment is severe. PEI is cheaper, machines well and covers 170 °C comfortably; above that it loses stiffness and PEEK is the material, at roughly double the price.
- Why is it amber and does that matter?
- The colour is inherent to the polymer and it is usually cosmetic. What matters more is that it is translucent enough to inspect some parts visually, and that UV exposure yellows it further over time.