Ultra-high-performance thermoplastic
PAI Polyamide-Imide
Grade-specific PAI stock shapes for demanding combinations of elevated temperature, mechanical load, creep control, wear and dimensional precision.
What is PAI?
Strength and Stability for Demanding Thermal-Mechanical Duty
Polyamide-imide is an amorphous, high-performance thermoplastic selected when conventional engineering plastics no longer provide enough strength retention, creep resistance, wear performance or dimensional stability.
Suitable PAI grades can operate at very high temperatures, with published grade families commonly reaching approximately 275°C under defined conditions. This is not a universal design temperature: geometry, load, exposure time, moisture, processing and the exact grade all affect the usable limit.
PAI also absorbs moisture. Drying, conditioning and dimensional allowances should be considered for precision parts and final inspection.
Elevated-temperature strength
PAI is considered where stiffness and load-bearing performance must be retained beyond the range of many engineering plastics.
Creep and dimensional control
Reinforced grades can support low thermal expansion and improved dimensional stability under sustained loading.
Wear-grade options
Bearing formulations are available for bushings, wear pads, seals and sliding parts after pressure, speed and mating surfaces are reviewed.
Machinable stock shapes
PAI is supplied as rod, sheet or plate, with tubes and molded blanks available through selected production routes and grades.
Grade-family selection
Choose the Formulation Before Comparing Data
Unfilled, reinforced and bearing grades solve different problems. Values from one formulation should not be applied to another.
Unfilled PAI
Balances high strength, toughness and electrical properties without fiber reinforcement.
- Precision structural parts
- Electrical components
- High-load fasteners and insulators
Glass-fiber-reinforced PAI
Selected when higher stiffness, lower expansion and improved dimensional control are more important than maximum toughness.
- Precision supports
- Electrical and thermal structures
- Load-bearing components
Carbon-fiber-reinforced PAI
Considered for high modulus, reduced thermal expansion and dimensionally demanding structural applications.
- Fixtures and structural parts
- Precision mechanical supports
- Components under sustained load
Bearing and wear PAI
Uses friction- and wear-focused fillers for sliding duty. Final selection requires the full tribological system.
- Bushings and bearings
- Wear rings and seal components
- Thrust washers and wear pads
PAI supply forms
Select Stock Around the Finished Geometry
Availability depends on grade, manufacturing route and dimensions. Confirm the exact size and stock status during quotation.
PAI Rod
Starting stock for turned parts, bushings, bearings, rings, fasteners, seal components and round structural parts.
PAI Sheet and Plate
Used for fixtures, test sockets, wear pads, structural plates and flat or profiled high-temperature components.
PAI Tube and Molded Blanks
Compression-molded tubes and blanks can reduce material removal for large rings, sleeves, bearings and special geometries.
Machined PAI Components
Send the drawing, tolerances, inspection requirements and operating conditions. Material condition, moisture control, machining sequence and post-cure history can affect final dimensions and performance.
Technical selection checklist
Verify These Items Against the Exact Grade TDS
A single generic PAI property table is not sufficient for design. Compare test method, specimen condition and temperature as well as the headline value.
| Selection topic | What to confirm | Why it matters | Quotation input |
|---|---|---|---|
| Temperature | Continuous, peak and cycling temperature under load | Usable limits depend on stress, time and the exact grade | Temperature profile and exposure duration |
| Mechanical load | Tensile, compressive, bending, impact and sustained load | Unfilled and reinforced grades behave differently | Load direction, magnitude, safety factor and life |
| Wear system | Pressure, speed, lubrication, mating material and finish | Wear is a system result, not a material-only property | PV condition, cycle, lubricant and counterface |
| Moisture | Conditioning, drying, storage and inspection condition | Moisture can affect dimensions and mechanical properties | Environment, tolerance and inspection standard |
| Chemicals | Medium, concentration, temperature and contact duration | Broad compatibility statements can hide grade limitations | Full chemical list and cleaning process |
| Compliance | Flammability, traceability and industry-specific documents | Certifications apply to specific grades and thicknesses | Required standard, report and lot documentation |
PAI applications
Components That Combine Heat, Load, Wear and Precision
The correct grade depends on the component duty. These application groups are starting points for technical review.
Aerospace and transportation
Fasteners, bushings, wear components, structural supports and parts exposed to combined thermal and mechanical duty.
Semiconductor and electronics
Test sockets, nests, insulating structures, precision fixtures and dimensionally controlled electrical components.
Bearings and wear parts
Bushings, bearings, thrust washers, wear pads and seal components after pressure, speed and counterface are evaluated.
Automotive and powertrain
Thrust washers, seal rings, transmission wear parts and high-temperature structural or electrical components.
Energy and industrial equipment
Compressor parts, labyrinth seals, backup rings, wear components and electrical parts for demanding equipment environments.
PAI or PEEK?
Decide by the Dominant Failure Risk
Neither material is universally better. Compare the exact grades at the operating temperature and component condition.
High-temperature strength, stiffness, creep control or specialized wear performance is the primary design driver.
Chemical resistance, lower moisture uptake, toughness or a broader range of semi-finished shapes is more important.
Test method, temperature, moisture condition, reinforcement, wear fillers, post-cure, geometry and machining history.
Prototype the finished geometry when tolerances, wear, sealing, safety or long-term load are critical.
Quotation workflow
Define the Grade, Condition and Inspection Method
Share the application
Provide temperature, load, chemical exposure, moisture, electrical duty and expected service life.
Confirm the grade family
Select unfilled, reinforced or wear-focused PAI and request the exact TDS and traceability documents.
Match the stock form
Choose rod, sheet, tube or molded blank based on finished geometry, allowance, material utilization and quantity.
Set machining and inspection conditions
Define drying, intermediate stress relief, final conditioning, measurement environment, tolerances and reporting.
PAI FAQ
Questions Before Ordering PAI Stock
The grade name, processing route and material condition are as important as the polymer family.
Is PAI the same material as Torlon®?
Can every PAI grade operate continuously at 275°C?
Which PAI grade is best for bearings?
Why does moisture matter for PAI machining?
What information is needed for a PAI quotation?
Torlon® is a registered trademark of Syensqo. Use of the name on this page is for material identification only.
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