PEI

High performance PEI for precision parts, combining excellent heat resistance, dimensional stability, and electrical insulation.

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PEI in Machining

PEI (Polyetherimide) is a high performance engineering thermoplastic known for its excellent heat resistance, dimensional stability, electrical insulation, and chemical resistance. PEI plastic is well suited for precision machined components that must maintain reliable performance under demanding temperature and mechanical conditions.

PEI is commonly supplied in rods, sheets, and plates and can be CNC machined into complex components with tight dimensional requirements. Its combination of high temperature resistance, strength, electrical insulation, and low moisture absorption makes it a popular material for demanding industrial applications.

At Longwang, we provide CNC machining of PEI rods and other PEI stock materials for custom prototypes, low-volume production, and high-precision components. From material selection and DFM review to precision machining, inspection, and finishing, we support your project from design to finished part.

strengthGood

processabilityExcellence

corrosion resistanceExcellent

typical applicationsShell, bracket, heat sink

Machined PEI

PEI, short for Polyetherimide, is an amorphous high-performance thermoplastic used in applications where conventional engineering plastics cannot provide sufficient thermal, mechanical, or dimensional performance.

Tensile Strength, Yield (MPa)Fatigue Strength (MPa)Elongation at Break (%)Hardness (Brinell)Density (g/cm³)

110 MPa45 MPa60%Rockwell M 1091.27 g/cm³

Surface Finishing Options for PEI

PEI is primarily selected for its inherent material properties rather than decorative surface finishing. Depending on the application, Longwang can provide suitable post-machining processes and appearance control.

As Machined

Standard finish, surface roughness of 3.2 μm (126 μin), removes sharp edges and deburs parts cleanly.

Tumbling

Utilizes barrel or vibratory processes with abrasives to smooth and polish the surface of parts.

Pros and Cons of PEI CNC Machining

PEI combines excellent heat resistance, high strength, dimensional stability, and electrical insulation. While it offers reliable performance in demanding applications, its higher cost, machining sensitivity, and limited chemical resistance should be considered during material selection.

pros

Excellent heat resistance and dimensional stability make PEI suitable for demanding precision applications.
High mechanical strength and stiffness provide reliable performance for precision machined components.
Excellent electrical insulation makes PEI a strong choice for connectors, insulators, and electronic parts.
Low moisture absorption helps PEI maintain dimensional accuracy in humid or changing environments.
Good flame resistance and chemical stability support reliable performance in demanding industrial applications.

cons

PEI is more expensive than common engineering plastics such as POM, nylon, and ABS.
PEI can be sensitive to machining heat, requiring controlled cutting parameters and proper cooling.
Its high hardness and stiffness can increase machining tool wear compared with softer plastics.
PEI has limited resistance to some strong chemicals, so compatibility should be checked before use.
Natural PEI typically has an amber color, which may limit options for applications requiring specific colors.

Applications of CNC Machined PEI Parts

PEI is used across industries where conventional plastics may not provide sufficient performance.

Electronics

Automotive

Medical Device

FAQs

Your Comprehensive Metal Manufacturing Solution Provider

Yes. PEI rods can be CNC turned and machined into precision components. Proper tooling, cutting parameters, fixturing, and temperature control are important for achieving stable dimensions and good surface quality.

Yes. PEI is designed for demanding thermal environments and maintains good dimensional and mechanical stability at elevated temperatures. The specific grade should be selected according to the actual operating temperature.

Natural PEI is typically amber or translucent amber. Black and other colors are also available for certain grades and applications.

Achievable tolerances depend on part geometry, dimensions, wall thickness, material grade, machining process, and inspection conditions. For critical dimensions, Longwang can review the drawing and recommend realistic machining tolerances.

Machining Material Resources

Guides, design tips, and best practices for efficient, high quality machining material resources.

ABS

strengthGood

processabilityExcellence

corrosion resistanceExcellent

typical applicationsShell, bracket, heat sink

strengthGood

processabilityExcellence

corrosion resistanceExcellent

typical applicationsShell, bracket, heat sink

Aluminum Alloy

strengthMedium

processabilityExcellence

corrosion resistanceExcellence

typical applicationsCNC Structural Frame, Optical Device Housing, Aerospace Structural Part

Aluminum in Sheet Metals

strengthMedium

processabilityExcellence

corrosion resistanceExcellent

typical applicationsLightweight Frame, Heat Dissipation Shield, Automotive Panel

Stainless Steel

strengthExcellence

processabilityGood

corrosion resistanceExcellence

typical applicationsMedical Implant Components, Fluid Manifold, Aerospace Shaft

Brass

strengthMedium

processabilityExcellence

corrosion resistanceGood

typical applicationsThreaded Fastener, Hydraulic Fitting, Electrical Connector Pin

Get in Touch With us

Helping customers grow steadily and achieve win-win development

Your trusted partner for CNC machining, sheet metal fabrication, stamping, and assembly. From prototyping to mass production with strict quality control.

tel:

0769-82763299

Mobile:

+86 18988716988

Email:

elena@lwmetalmachining.com

jane@lwmetalmachining.com

fax:

0769-82763199

Address:

No.3 Longze Road, Chang'an Town, Dongguan City, Guangdong Province, China,523861

Capabilities