PEI
Amorphous material with exceptional strength and rigidity under long term heat exposure
- Common grades
- Ultem 1000 (unfilled) · Ultem 2300 (30% glass-filled)
- Machinability
- PEI (best known as Ultem) delivers most of PEEK's virtues at a substantially lower price: continuous service around 170 °C, inherent flame resistance with low smoke, outstanding dimensional stability, and strong electri…
- Tolerances
- Agreed per grade at DFM: engineering plastics move with temperature and moisture, so critical fits are toleranced feature by feature
- Processes
- CNC milling, CNC turning and 5-axis machining
- Finishes
- Annealing · Machined finish · Cleanroom cleaning & packing
- Used in
- Automotive, Semiconductor, Medical
- Certification
- Manufacturer certificate of conformance and lot traceability with every shipment
Machining PEI
PEI (best known as Ultem) delivers most of PEEK's virtues at a substantially lower price: continuous service around 170 °C, inherent flame resistance with low smoke, outstanding dimensional stability, and strong electrical insulation. Amber and transparent, it is a fixture in automotive sensor housings, semiconductor tooling and sterilizable medical hardware.
It machines predictably to fine finishes, but as an amorphous polymer it is notch-sensitive and holds machining stress: annealing before final machining, generous radii and sharp tooling keep parts crack-free through their service life.
We hold ±0.05 mm on critical PEI features, machine unfilled and glass-filled grades, and deliver cleanroom-cleaned parts where semiconductor programs require it.
Common Grades We Machine
- Ultem 1000 (unfilled) - The standard transparent-amber grade: heat, flame rating and stability.
- Ultem 2300 (30% glass-filled) - Double the stiffness and tighter creep control for loaded fixtures and structures.
Applications by Industry
- Automotive - sensor housings, electrical insulators and high-temperature under-hood brackets.
- Semiconductor - high-heat handling fixtures, sockets and insulators.
- Medical - repeatedly sterilizable instrument components in certified grades.
Surface Finishing Options
- Annealing - stress relief before final machining; standard practice on precision PEI.
- Machined finish - fine surfaces off the tool; polishing available for transparent parts.
- Cleanroom cleaning & packing - washed and double-bagged for semiconductor delivery.
See our surface finishing services for the full range.
Frequently Asked Questions
PEI or PEEK: how do I choose?
PEEK wins on chemical resistance, wear and top-end temperature; PEI matches the stability and flame performance most applications actually need at roughly half the material cost. If chemistry and wear are mild, Ultem is the value answer.
Why do PEI parts need annealing?
As an amorphous polymer, PEI holds machining stress that can craze or crack at features later: annealing before finish machining removes it. It's standard in our PEI process.
Is PEI autoclavable?
Yes, for many cycles, though for products facing a lifetime of daily steam sterilization, PPSU holds up longer. We can advise per duty cycle.
Precision PEI Manufacturing in Singapore
Need complex PEI parts manufactured to tight tolerances? Explore our 5-axis simultaneous CNC machining, CNC milling, CNC turning and certified ISO Class 6–8 cleanroom assembly capabilities.
Speak with Our Sales & Engineering Team
Explore how Shine's Singapore precision CNC machining and cleanroom assembly integrate into your global supply chain. We welcome technical consultations, mutual NDAs, and facility audits.
- Mutual NDA executed within 24 hours
- ISO 9001:2015 certified & Cyber Essentials mark
- 24–48h engineering DFM feedback & formal RFQ pricing