Polyetherimide (PEI), 30% Glass-Fiber Reinforced
PEI GF30 is a heavily reinforced PEI grade offering maximum stiffness and dimensional stability.
Select a form factor to view real-time inventory, pricing, and custom cut-to-size options.
| Short Description | Color | Diameter | Length | Stock | Price | Add to quote |
|---|---|---|---|---|---|---|
| Ultem GF30 (PEI GF30) - 0.250" dia x 120 Natural Rod | Natural | 0.250″ | 120″ | Out of stock | Contact | |
| Ultem GF30 (PEI GF30) - 0.375" dia x 120 Natural Rod | Natural | 0.375″ | 120″ | Out of stock | Contact | |
| Ultem GF30 (PEI GF30) - 0.500" dia x 120 Black Rod | Black | 0.500″ | 120″ | Out of stock | Contact | |
| Ultem GF30 (PEI GF30) - 0.500" dia x 120 Natural Rod | Natural | 0.500″ | 120″ | Out of stock | Contact | |
| Ultem GF30 (PEI GF30) - 0.500" dia x 60 Natural Rod | Natural | 0.500″ | 60″ | Out of stock | Contact | |
| Ultem GF30 (PEI GF30) - 0.500" dia x 84 Natural Rod | Natural | 0.500″ | 84″ | Out of stock | Contact | |
| Ultem GF30 (PEI GF30) - 0.750" dia x 120 Natural Rod | Natural | 0.750″ | 120″ | Out of stock | Contact | |
| Ultem GF30 (PEI GF30) - 0.750" dia x 60 Natural Rod | Natural | 0.750″ | 60″ | Out of stock | $101.39per rod | |
| Ultem GF30 (PEI GF30) - 1.000" dia x 108 Natural Rod | Natural | 1.000″ | 108″ | Out of stock | $326.55per rod | |
| Ultem GF30 (PEI GF30) - 1.000" dia x 120 Natural Rod | Natural | 1.000″ | 120″ | Out of stock | $362.83per rod |
Material Overview
PEI GF30 is the most heavily reinforced grade in the polyetherimide (PEI) family, incorporating 30% glass fiber by weight to deliver maximum stiffness, high mechanical strength, and exceptional dimensional stability under sustained mechanical and thermal load. This grade is selected when structural integrity and minimal deflection must be maintained at the upper limit of the polyetherimide service range — where lower-filled grades or unfilled PEI cannot provide the required rigidity, dimensional control, or resistance to creep. It is a common choice for aerospace structural brackets, semiconductor equipment frames, and high-voltage electrical housings where both mechanical and thermal demands are highest.
PEI GF30 achieves 19,500 psi tensile strength, 28,000 psi flexural strength, and a flexural modulus of 797,000 psi — a significant step above the 493,000 psi modulus of unfilled PEI. Short-term service temperature reaches 390°F (200°C), backed by a glass transition temperature of 415°F (213°C) and a long-term service temperature of 335°F (170°C). Water absorption at 24 hours immersion is extremely low at 0.04%, supporting precise and stable components in humid environments. The material carries inherent UL 94 V-0 flame resistance, with surface and volume resistivity both at 10¹⁴ Ω, providing reliable electrical insulation in structural electronics housings. Density is 1.51 g/cm³ (0.054 lb/in³), moderate for a heavily reinforced structural grade.
Machining considerations. The 30% glass content makes PEI GF30 the most abrasive grade in the polyetherimide family. Carbide or ceramic tooling is required; tool life is reduced and rigid fixturing is essential for maintaining tight tolerances across a production run. Despite these demands, PEI GF30 is regularly machined into complex structural components for aerospace, semiconductor, and defense electronics. Controlled cutting speeds, sharp tool edges, and positive-rake geometries help manage surface quality and dimensional accuracy. Coolant use and frequent tool inspection are recommended for sustained production-volume machining operations.
Grade selection within the PEI family. PEI GF30 is the right choice when maximum stiffness and dimensional stability are the primary design drivers and the machining process can accommodate a heavily reinforced abrasive material. When intermediate reinforcement is sufficient, PEI GF10 or PEI GF20 offer easier machining and better impact toughness. For cleanroom-grade requirements in unfilled form, see PEI CRS.
Technical Specifications
Typical values at 23°C / 50% RH. Values are nominal and not guaranteed; refer to lot-specific certificates of conformance for production parts.
Frequently Asked Questions
PEI GF30 is polyetherimide with 30% glass-fiber reinforcement — the maximum reinforcement level in the PEI family. It delivers 19,500 psi tensile strength, 28,000 psi flexural strength, a flexural modulus of 797,000 psi, and short-term service temperature of 390°F (200°C). Inherent UL 94 V-0 flame resistance and a very low water absorption of 0.04% (24 h) round out its performance for demanding structural applications.
PEI GF30 has significantly higher stiffness (flexural modulus 797,000 psi vs. 493,000 psi for unfilled), lower thermal expansion, and better resistance to creep. Unfilled PEI is tougher, machines more easily, and offers better electrical insulation. Choose GF30 for maximum structural performance; choose unfilled PEI for best machinability and toughness.
Yes, but the 30% glass content requires carbide or ceramic tooling, rigid fixturing, and careful feed rate control to manage abrasive tool wear and maintain part tolerances. It is regularly machined into aerospace brackets, semiconductor equipment frames, and structural housings where high-performance materials are required.
Ready Plastics stocks PEI GF30 in sheet form. Consult the datasheet or contact us for current thickness ranges and custom-cut availability.
Yes. With a short-term service temperature of 390°F (200°C) and a glass transition temperature of 415°F (213°C), PEI GF30 retains structural integrity well beyond the capability of most engineering thermoplastics. Its very low water absorption (0.04% at 24 h) and high flexural modulus make it a reliable choice for precision structural components in demanding thermal environments.
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