PAI Rod — Diameters, Lengths & Tolerances
PAI rod is round bar stock produced from polyamide-imide (PAI), one of the highest-performing engineering thermoplastics available. PAI maintains exceptional mechanical strength, dimensional stability, and structural integrity at temperatures exceeding 250 °C (482 °F), making it the material of choice for precision components in aerospace, semiconductor fabrication, and demanding industrial applications where other engineering plastics fall short.
At a glance:
- Diameter range: standard rod sizes available (see datasheet for full size list)
- Standard lengths: standard cut lengths available
- OD tolerance: close commercial tolerances maintained
- Material: Polyamide-Imide (PAI)
- Color: Amber/tan (natural); black grades available
- Continuous service temperature exceeds 250 °C / 482 °F
Standard Diameter Table
PAI rod is stocked in selected standard diameters to support precision turning and grinding operations. Because PAI is a high-performance and higher-cost material, diameter range is focused on common application sizes:
| Diameter | Notes |
|---|---|
| 1/4" (0.250") | Precision pins, small components |
| 1/2" (0.500") | Bushings, standoffs |
| 1" (1.000") | Structural machined parts |
| 1.5" (1.500") | Larger precision components |
| 2" (2.000") | Heavier section parts |
| 3" (3.000") | Large diameter precision stock |
Consult Ready Plastics for current size availability. PAI rod is typically machined on precision CNC lathes; grinding is recommended for final sizing to tight tolerances.
Properties
PAI delivers a combination of high-temperature performance and mechanical strength not available from standard engineering thermoplastics:
| Property | Value |
|---|---|
| Continuous service temperature | >250 °C / >482 °F |
| Outstanding wear resistance | Yes |
| Low thermal expansion | Yes |
| Strong dimensional stability | Yes |
| Chemical resistance | Excellent in most industrial environments |
| Density | Refer to grade datasheet |
PAI brief does not include specific numeric property values at this time. Consult the Ready Plastics PAI datasheet or contact our technical team for grade-specific property tables.
Typical Applications
PAI rod is machined into precision components for the most demanding thermal and mechanical environments:
- Aerospace structural components — maintains strength and geometry at elevated temperatures
- Semiconductor wafer-handling components — dimensional stability and chemical resistance in process environments
- High-temperature pump and valve components — performs where PEEK and nylon cannot sustain service
- Precision bearing cages and retainers — low thermal expansion preserves bearing clearances at operating temperature
- Turbine and compressor wear parts — wear resistance under high-speed contact at elevated temperatures
- Test fixtures and precision tooling — dimensional stability across wide temperature swings in lab environments
Machining PAI Rod
PAI rod requires sharp, high-quality carbide tooling and precision machining practices. The material is harder than most engineering thermoplastics and behaves more like a filled thermoset during cutting. Use low feed rates and moderate cutting speeds; dull tooling causes heat buildup that can affect dimensional accuracy. Grinding is the preferred method for achieving tight-tolerance OD dimensions. PAI generates abrasive dust during machining — use proper dust control and respiratory protection. Allow parts to thermally stabilize before final inspection.