PI Plastic Materials

PI Plastic Sheet, Rod, Tube & Custom CNC Parts

High-performance polyimide materials and precision-machined components for high-temperature, wear-resistant, electrical insulation, vacuum, and precision applications.

PI (polyimide) is a high-performance engineering plastic. Great Plastics supplies polyimide stock shapes, including sheets, rods, and tubes, as well as custom CNC-machined PI components.

±0.01mm

machining tolerance

24h

RFQ response after drawings and application conditions are received

5-7 days

fast dispatch capability for suitable stock-form orders

1 piece

MOQ (Min. Order)

Overview

Why Engineers Specify PI Plastic Materials

PI is generally considered when a component must operate under a combination of high temperature, low friction, wear conditions, vacuum environments, electrical requirements, and tight dimensional control.

Continuous High-Temperature Applications

These applications may include thermal processing equipment, semiconductor components, and precision machinery.

Wear and Friction-Controlled Components

PI is considered for sliding components where lubrication is limited, friction control is important, or dimensional stability must be maintained.

Precision Components in Demanding Environments

PI can support precision components where thermal expansion, moisture response, and geometry retention influence long-term performance.

Available Forms

PI Plastic Forms & Custom Parts

Great Plastics supplies polyimide in standard stock shapes and custom-machined forms. Available material options include unfilled and filled PI grades selected according to temperature, wear, friction, electrical, and mechanical requirements.

PI-plastic sheet for precision machining and insulation components

PI Sheet

PI sheet and plate stock for insulation components, spacers, covers, wear parts, and precision-machined components.

  • Insulation plates
  • Precision components
  • Covers & spacers

PI Rod

Round PI stock for CNC-machined bushings, bearings, seals, rollers, and other cylindrical components.

  • Bushings
  • Bearings
  • Seals & rollers
PI plastic tube stock for chemical resistant and insulating applications

PI Tube

PI tube stock for sleeves, insulation components, bushing bodies, and other parts requiring accurate internal dimensions.

  • Sleeves
  • Insulation components
  • Bushing bodies
custom CNC machined PI plastic parts manufactured for OEM applications

Machined Components

CNC-machined PI components manufactured according to customer drawings, specifications, material requirements, and tolerance requirements.

  • CNC machined parts
  • OEM requirements
  • Prototype to production

Material Selection

PI Material Grades & Filler Selection

PI grades can be formulated with different fillers to modify friction, wear resistance, stiffness, and load capacity. Grade selection depends on the primary operating requirements.

PI Grade / Filler Selection Table
GRADE / FILLER BEST FOR AVOID WHEN RFQ INPUTS
Virgin (unfilled) PI Maximum temperature, best electrical insulation and dimensional stability Lowest cost or impact toughness is the priority Service temperature, electrical & vacuum requirements
Graphite-filled PI Dry-running wear: bearings, bushings, seal rings Lowest friction coefficient matters more than wear life Sliding speed, PV factor, counterface material
PTFE-filled PI Lowest-friction sliding and sealing: wear rings, seals High-load structural duty Friction requirement, media, temperature
Carbon fiber reinforced PI High-load, high-stiffness aerospace and mechanical parts Where electrical insulation is required (carbon fiber conducts) Load, stiffness, environment
Glass-filled / MoS2-filled PI Tailored stiffness or friction (available on request) — Application detail for compound selection

Performance Data

PI Plastic Material Properties

Typical properties for an unfilled (virgin) polyimide grade. Actual values depend on the specific material grade, test method, and processing conditions.

Material Properties Table
PROPERTY TEST METHOD TYPICAL VALUE UNIT
Physical Properties
Density ISO 1183 ~1.43 g/cm³
Water absorption (24 h) ASTM D570 ~0.24 %
Mechanical Properties
Tensile strength (23 °C) ASTM D638 ~87 MPa
Tensile modulus ASTM D638 ~2.5 GPa
Flexural strength ASTM D790 ~110 MPa
Compressive strength ASTM D695 ~117 MPa
Elongation at break ASTM D638 ~7.5 %
Hardness Shore D ~92 Shore D
Thermal Properties
Glass transition temperature DSC ~360 °C
Continuous service temperature — ~260 °C
Short-term peak temperature — ~400 °C
Coefficient of thermal expansion ASTM E831 ~54 ppm/K
Electrical Properties
Dielectric strength ASTM D149 ~22 kV/mm
Volume resistivity ASTM D257 >1014 Ω·cm

Note: Actual values depend on the specific PI grade, formulation, processing method, test standard, and application conditions.

Manufacturing Capability

PI Machining and Custom PI Parts

Precision PI components require both suitable material selection and controlled machining. Great Plastics supports PI machining from stock material to finished components.

PI can be machined into complex, close-tolerance components, but its hardness and low thermal conductivity require careful control of cutting conditions. Appropriate tooling, feeds, speeds, workholding, and heat management help maintain dimensional accuracy and surface quality.

CNC Milling & Turning
Precision Machining
Tight Tolerance Parts
Prototype Production
OEM Volume Manufacturing
Multi-Axis Machining

Typical PI components include bushings, bearings, seals, wear rings, insulators, sleeves, and wafer-handling components. Prototype, low-volume, and OEM production quantities are supported.

1–10,000+
Parts per Run
CMM
Inspection
24h
Quote Turnaround

custom Selection

Custom PI Precision Components

Successful custom PI component production depends on clear drawing definition, including critical surfaces, datum structures, tolerance requirements, and functional areas.PI components should be evaluated according to load, speed, mating materials, temperature exposure, vacuum or dry gas environments, and whether the component functions primarily as a wear part or electrical insulator.

Bearings and Bushings

Filled PI grades may be considered for bearings and bushings where load, speed, mating surfaces, and wear requirements justify the material selection.

Seal Rings and Wear Rings

PI can be considered for seal rings and wear rings where temperature capability, friction control, and dimensional stability exceed the practical limits of standard plastics.

Insulation Components

Unfilled PI or suitable electrical grades may be considered for insulation components where voltage, thickness, temperature, and dimensional requirements are defined.

Precision Fixtures

PI is used for precision fixtures in semiconductor, aerospace, and high-temperature applications where geometry retention and thermal stability are important.

Industry Use Cases

Applications of PI Plastic Materials

PI is used in applications requiring high-temperature stability, wear resistance, electrical insulation, low outgassing, and dimensional stability. Typical applications include semiconductor equipment, aerospace, electrical and electronics, and industrial machinery.

Semiconductor Equipment

Parts

  • Wafer handling components
  • High temperature fixtures
  • Insulation and vacuum parts

why PI

Low outgassing, chemical resistance, and dimensional stability for high-temperature and precision handling applications.

RFQ factors

Cleanliness requirements, process media, temperature cycling, and tolerances.

Aerospace Applications

Parts

  • Bearings and seals
  • Structural components
  • Insulating elements

why PI

Low weight compared with metals, high-temperature stability, and resistance to selected radiation environments.

RFQ factors

Service temperature, load, operating environment, and certification requirements.

Electrical & Electronics

Parts

  • Insulation parts
  • High temperature connectors
  • Insulating sleeves

why PI

Stable electrical insulation at elevated temperatures, high dielectric strength, low creep, and good dimensional stability.

RFQ factors

Voltage, temperature class, insulation requirements, and operating environment.

Industrial Machinery

Parts

  • Bearings and bushings
  • Wear rings and seals
  • Sliding components

why PI

Good wear resistance, high-temperature performance, and resistance to selected process media for demanding mechanical applications.

RFQ factors

Speed, load, lubrication conditions, mating surface, and operating temperature.

Material Comparison

PI vs. Other Engineering Plastics

The table below compares PI with commonly selected high-performance engineering plastics. Material selection depends on temperature, mechanical load, chemical exposure, wear, machinability, and cost.

High-Performance Polymer Comparison Table
FACTOR PI PEEK PPS PTFE PAI
Typical continuous temperature ~260 °C ~250 °C ~220–240 °C ~260 °C ~250 °C
Mechanical strength High High Moderate Low Highest
Wear / friction tuning Excellent with fillers Excellent Good Lowest friction Excellent
Chemical resistance Good Outstanding Outstanding Outstanding Good
Electrical insulation Excellent Excellent Good Excellent Good
Machinability Demanding Easier Easier Easy Demanding
Relative cost High Medium Lower Medium Highest
Best when Highest temp, wear, insulation Tough, broad chemical, economy Cost + solvent resistance Lowest friction, inert Highest strength / temp duty

PI is often selected for high-temperature, wear, electrical insulation, and dimensional stability requirements. PEEK offers easier machining and a broader balance of mechanical and chemical performance, while PPS is commonly selected for chemical resistance and dimensional stability. PTFE is preferred where low friction is the primary requirement, and PAI is used for demanding strength and temperature applications. Final material selection should be confirmed against the applicable grade datasheet and operating conditions.

Your Partner

Why Choose Great Plastics

From material selection to volume production, we support industrial OEMs with engineering expertise, precision machining, and reliable supply.

01

Engineering Support

Support for selecting PI grades according to temperature, chemical, electrical, load, wear, and machining requirements.

02

Material Selection

Guidance across unfilled, glass-filled, carbon-filled, wear-modified, and specialty PI grades based on application requirements.

03

Custom Manufacturing

PI stock shapes and custom-machined components are available for prototype, low-volume, and production requirements.

04

Quality Control

Quality requirements are reviewed according to drawings, material specifications, tolerances, inspection methods, and application requirements.

Request a Quote for Custom PI Plastic Components

Send your drawings, specifications, or part samples to our engineering team.

We’ll respond with material recommendations, pricing, and lead times within one business day.

Common Questions

Frequently Asked Questions

Quick answers to the questions engineers and procurement teams ask most about PI materials.

How high temperature can PI withstand?

Depending on the grade and operating conditions, thermoset polyimide can provide continuous service at approximately 260°C, with selected grades capable of short-term exposure to significantly higher temperatures. Actual temperature capability depends on the grade, filler system, load, and exposure time.

PI and PEEK are suited to different applications. PI generally provides higher temperature capability and good wear and electrical insulation performance, while PEEK is easier to machine and offers a strong balance of mechanical, chemical, and thermal properties. Material selection depends on temperature, load, wear, chemical exposure, and cost.

Yes. PI can be CNC machined into precision components, including bushings, bearings, seals, insulators, sleeves, and wear rings. Because polyimide is hard and has low thermal conductivity, appropriate tooling, cutting conditions, workholding, and heat control are required for close-tolerance machining.

Typical PI applications include semiconductor wafer-handling components, high-temperature fixtures, vacuum components, aerospace bearings and seals, electrical insulation parts, and industrial wear components.

Send your drawing or 3D model, required PI grade, material form, dimensions, quantity, and operating conditions through our quote form. Our engineering team will review the requirements and confirm suitable material and machining options.