Precision PEI Machining for High-Temperature & High-Performance Applications
Custom CNC Machined PEI (Ultem®) Components with Tight Tolerances and Fast Lead Times.
STEP / STP / IGS / X_T accepted · NDA available
What Is PEI (Polyetherimide)?
Machining of PEI
PEI, commonly known by the trade name Ultem®, is a high-performance amorphous thermoplastic recognized for its exceptional mechanical strength, dimensional stability, electrical insulation properties, and resistance to elevated temperatures.
Unlike conventional plastics, PEI maintains its structural integrity even under continuous exposure to temperatures exceeding 170°C.
Its unique combination of strength, heat resistance, and machinability makes it a preferred material in semiconductor equipment, medical devices, aerospace systems, electronics, and industrial automation.
Please contact our sales and technical teams to learn about how we can provide high-quality machining PEI Engineering plastic services at a fair and competitive price.
Key Properties of PEI Material
| Property | Typical Value |
| Continuous Service Temperature | 170°C |
| Glass Transition Temperature | 217°C |
| Tensile Strength | 105 MPa |
| Density | 1.27 g/cm³ |
| Electrical Insulation | Excellent |
| Flame Rating | UL94 V-0 |
| Sterilization Resistance | Excellent |
| Dimensional Stability | Outstanding |
Why Choose PEI for Precision Components?
Exceptional Heat Resistance
PEI maintains mechanical performance and dimensional accuracy in environments where many engineering plastics soften or deform.
Ideal for:
- High-temperature electrical assemblies
- Semiconductor processing equipment
- Medical sterilization systems
Excellent Mechanical Strength
PEI combines high stiffness with outstanding impact resistance, making it suitable for structural applications requiring lightweight alternatives to metal.
Applications include:
- Fixture components
- Structural brackets
- Equipment housings
- Precision assemblies
Superior Electrical Insulation
PEI offers excellent dielectric properties, making it widely used in electrical and electronic applications requiring reliable insulation performance.
Common uses include:
- Insulators
- Connector bodies
- Sensor housings
- Semiconductor fixtures
Outstanding Dimensional Stability
PEI exhibits low thermal expansion and minimal moisture absorption, ensuring consistent performance in precision assemblies.
PEI Machining Capabilities
Welcome to PlasticPartsCustom, your trusted partner for high-performance PEI machining capabilities. Our state-of-the-art CNC machines and experienced team of engineers and technicians enable us to produce high-precision, complex parts with tight tolerances and exceptional surface finishes, using PEI, a high-performance engineering thermoplastic.
CNC Milling
Our multi-axis machining centers produce complex PEI components with tight tolerances and excellent repeatability.
CNC Turning
We manufacture precision rotational PEI components including:Bushings, Sleeves, Spacers, Insulators, Connector Components
Precision Hole Machining
For applications requiring accurate alignment and assembly:Reamed Holes
Threaded Features, Precision Bores, Tight Positional Tolerances
PEI Grades We Machine
Ultem® 1000
A general-purpose unfilled PEI grade offering excellent strength, heat resistance, and electrical properties.Typical applications:
- Medical equipment
- Semiconductor fixtures
- Electrical insulators
- Structural components
Ultem® 2300
30% glass fiber reinforced PEI providing enhanced stiffness and dimensional stability.Typical applications:
- Automation equipment
- Precision tooling
- Semiconductor processing systems
Custom PEI Materials
We support machining of:
PEI Rod
PEI Sheet
Ultem 1000
Ultem 2100
Ultem 2200
Ultem 2300
Material certifications available upon request.
PEI Parts We Manufacture
Our PEI machining services support a wide range of custom applications.
Semiconductor Components
- Surgical instrument parts
- Sterilization trays
- Diagnostic equipment components
- Laboratory equipment assemblies
Medical Device Components
- Surgical instrument parts
- Sterilization trays
- Diagnostic equipment components
- Laboratory equipment assemblies
Aerospace Components
- Lightweight structural parts
- High-temperature electrical supports
- Flame-resistant assemblies
Industrial Automation Components
- Robot end-effector components
- Sensor mounting brackets
- Precision guides
- Fixture systems
Common PEI Machining Challenges We Solve
Our PEI machining services support a wide range of custom applications.
Preventing Stress Cracking
PEI can develop internal stress during machining if cutting parameters are not properly controlled.
Our machining strategy minimizes stress concentration and improves long-term reliability.
Maintaining Tight Tolerances
PEI’s thermal characteristics require precise machining techniques and process control.
Our experienced machinists and inspection procedures ensure dimensional consistency.
Achieving High Surface Quality
Specialized tooling and optimized cutting parameters help deliver superior surface finishes without compromising part integrity.
Quality Assurance
Every PEI component is manufactured under our ISO 9001:2015 quality management system.
Inspection equipment includes:
Mitutoyo CMM
Digital Height Gauges
Micrometers
Calipers
Optical Measurement Equipment
Available documentation:
Material Certificates Certificate of Conformance (COC) First Article Inspection (FAI) Dimensional Inspection Reports
Why Engineers Choose PlasticPartsCustom
| Tight Tolerance Expertise Achievable tolerances up to ±0.01mm. |
| No MOQ Requirements From a single prototype to low-volume production runs. |
| Fast Turnaround Typical prototype lead times from 5–7 working days. |
| Material Expertise Extensive experience machining PEI, PEEK, POM, PTFE, PPS, and other engineering plastics. |
| Reliable Quality Consistent production supported by ISO 9001:2015 procedures and in-process quality control. |
Industries We Serve
- Semiconductor Equipment
- Medical Devices
- Industrial Automation
- Aerospace
- Electronics
- Scientific Instruments
- Energy Systems
PEI vs PEEK: Which High-Performance Plastic Is Right for Your Project?
PEI (Ultem) and PEEK are both high-performance engineering plastics for demanding applications, but they differ in temperature range, mechanical strength, and cost. This comparison helps you choose the right material.
| Property | PEI (Ultem) | PEEK |
|---|---|---|
| Max Service Temperature | 170°C (338°F) | 250°C (480°F) |
| Tensile Strength | 105 MPa | 95-100 MPa |
| Density | 1.27 g/cm³ | 1.30 g/cm³ |
| Flame Rating | UL94 V-0 (inherent) | UL94 V-0 |
| Chemical Resistance | Good | Excellent |
| Wear Resistance | Good | Excellent |
| Dimensional Stability | Outstanding | Excellent |
| Sterilization Resistance | Excellent (steam, gamma, EtO) | Excellent (steam, gamma, EtO) |
| Machinability | Excellent | Good (requires experience) |
| Relative Cost | $$ | $$$$ |
| Best For | Aerospace interiors, medical devices, electrical components, high-heat applications | Medical implants, semiconductor, aerospace, extreme temperature and chemical environments |
Choose PEI (Ultem) if you need excellent flame resistance, dimensional stability, and a lower-cost alternative to PEEK for applications up to 170°C. Choose PEEK if your application requires higher continuous operating temperature (250°C), superior chemical resistance, or biocompatibility for medical implants.
Not sure which material fits your project? Send us your drawing for a free material recommendation.
Related Materials
Explore other engineering plastics we machine:
| Material | Key Properties | Best For |
|---|---|---|
| PEEK | Higher temp 250°C, chemical resistant | Medical implants, extreme environments |
| PC (Polycarbonate) | Impact resistant, transparent, 130°C | Safety shields, housings, medical devices |
| PSU (Polysulfone) | Steam sterilizable, hydrolysis resistant | Medical, laboratory, food processing |
Frequently Asked Questions
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Request a Quote for PEI Machined Parts
Whether you need a single prototype or a low-volume production run, our engineering team can help evaluate your design and provide a competitive quotation.
Simply Send Us:
- 2D Drawings (PDF)
- 3D Files (STEP, STP, IGES, X_T)
- Quantity Requirements
- Material Specifications
What You Will Receive
- DFM Feedback
- ✓ Competitive Pricing
- ✓ Lead Time Confirmation
- ✓ Inspection Plan
- ✓ Engineering Support