PEI plastic material

Choose PEI plastic for heat, flame resistance and electrical insulation.

PEI plastic, widely known through Ultem material grades, is used when parts need heat resistance, stiffness, electrical insulation and flame performance. Great Plastics reviews PEI sheet, rod, machined components and grade requirements before quoting.

PEI plastic rods sheets plates insulators spacers and machined parts for material review

Short answer

PEI is often the right review point when electrical and flame needs matter more than extreme wear.

PEI can give strong dimensional stability, heat resistance and insulation performance, especially for electrical, fixture, aerospace and industrial parts. The quote should clarify whether unfilled, glass-filled or another grade is needed before geometry and tolerance assumptions are fixed.

Selection signals

Review the material fit before the drawing becomes a quote.

Ultem context

Ultem is a PEI trade name often used in drawings, sourcing notes and material discussions.

Electrical insulation

Review voltage, spacing, moisture, heat and documentation expectations before selecting grade.

Flame behavior

Clarify flame, smoke, regulatory or customer approval needs before quoting production parts.

Glass-filled grades

Glass-filled PEI may improve stiffness but can affect edge quality, tool wear and small features.

Alternative check

Compare PEI with PEEK, PPS, PAI, PI or PC/PSU/PPSU when cost or exposure changes.

Material comparison

Compare PEI with nearby engineering plastics before committing to the grade.

Material route When it fits RFQ note
PEI / Ultem Heat, flame behavior, electrical insulation, stiffness and dimensional stability Send electrical, flame, heat and tolerance requirements.
PEEK Higher chemical and wear performance for demanding environments Review when PEI does not cover chemicals, wear or high-performance load.
PPS Chemical stability and repeat molding economics Review for chemically exposed electrical or equipment parts.
PAI Severe load, wear and creep resistance Use when mechanical performance exceeds PEI capability.
PI Specialty high-heat, dry wear, vacuum or electrical applications Use when PEI temperature or specialty behavior is not enough.

RFQ details

Send the PEI details that affect grade, machining and inspection.

  • Drawing, CAD model or sample photo
  • Ultem or PEI grade if specified, including unfilled or glass-filled target
  • Temperature, flame, electrical, moisture and chemical exposure conditions
  • Critical tolerances, thin walls, threads, sharp corners and finish expectations
  • Quantity, project stage, documentation and packaging requirements
PEI plastic rods sheets plates insulators spacers and machined parts for material review

FAQ

Questions buyers ask before selecting this material.

Is Ultem the same as PEI?

Ultem is a well-known trade name for PEI, or polyetherimide. Drawings may use either term when specifying the material.

Yes. PEI can be machined into insulators, spacers, fixtures, panels and precision parts, but grade, feature size and tolerance requirements should be reviewed.

PEI may be a better fit when flame behavior, electrical insulation, dimensional stability and cost matter more than PEEK-level chemical or wear performance.

Send the drawing, grade or Ultem reference, quantity, electrical or flame requirements, operating temperature and critical tolerances.

Material RFQ

Send drawings, material targets and operating conditions before sourcing decisions are locked.

Great Plastics can review the material choice, product form, machining route and RFQ details before quoting your next engineering plastic part.