# PEI (Ultem 1000)

> The thinking engineer's high-performance pick: amber-transparent, flame-rated, autoclavable — at half the PEEK price.

- Category: Engineering Plastics → high-performance
- HTML page: https://fabvector.com/materials/pei-ultem (Portuguese: https://fabvector.com/pt/materials/pei-ultem)
- Price index: $$$$ (1–5, 6061-T6 = $)

## Mechanical properties (typical values, not certified minimums)

| Property | Value |
|---|---|
| Tensile strength | 110 MPa |
| Yield strength | ~105 MPa |
| Hardness | M109 (Rockwell) |
| Density | 1.27 g/cm³ |
| Machinability | ★★★☆☆ (3/5) |
| Corrosion resistance | ★★★★☆ (4/5) |

## When to choose it

You priced PEEK and flinched: PEI gives 170 °C continuous service, inherent flame resistance, repeated autoclaving and the highest strength of the amber polymers at roughly half the cost.

## When to look elsewhere

Service exceeds ~170 °C, chlorinated solvents are present, or impact toughness matters — PEI is notch-sensitive. Step to PEEK for chemistry and heat, PPSU for impact plus sterilization.

## Typical applications

- Reusable, steam-sterilizable medical device parts
- Aircraft interior components (FST-rated)
- Optical and sensor mounts with low outgassing
- High-temp electrical and semiconductor insulators

## Compatible surface finishes

- [As-Machined](https://fabvector.com/md/finishes/as-machined)
- [Laser Marking](https://fabvector.com/md/finishes/laser-marking)

Industries: medical-devices, aerospace, optics-photonics, semiconductors · Instant quote: https://fabvector.com/quote