Technical Comparison: PEEK, POM (Delrin), and PTFE
Lately, many clients from the electronics, aerospace, and medical sectors have been asking us which is the best material to use for their applications. It’s certainly challenging to give a general answer—it depends on the actual characteristics required and how much one is willing to invest. I won’t deny that PEEK has an exceptional allure. From the very first time we machined it, we fell in love with it. Finally, a plastic that allows for maintaining tight tolerances and offers exceptional machinability. However, as always, it’s not the best choice for every application.
This document provides a detailed technical comparison of PEEK, POM (Delrin), and PTFE, focusing on their mechanical resistance, thermal resistance, electrical and insulating characteristics, behavior in vacuum, machinability, and achievable precision. Additionally, specific guidelines for selecting these materials in the medical, aerospace, and electronics sectors are included to provide a comprehensive overview.
1. Mechanical Resistance

2. Thermal Resistance

3. Electrical and Insulating Properties

4. Behavior in Vacuum (Space)

5. Machinability

Sector-Specific Guidelines for Material Selection
1. Medical Sector
PEEK is an excellent choice in the medical sector for applications requiring biocompatibility, repeated sterilization, and high mechanical stability. It is widely used for implants, surgical instruments, and precise small components such as endoscopic parts. POM is better suited for disposable, low-cost items, while PTFE is ideal for chemically inert seals or gaskets.

Figure 1 - Figure 1 - Specific application engineered by Engmotion for a customer of Medical/Pharma Sector
2. Aerospace Sector
PEEK stands out in aerospace applications due to its high-temperature resistance, excellent strength-to-weight ratio, low outgassing, and durability in high-friction environments. It is ideal for aircraft engine components, thermal insulators, and structural parts in spacecraft. POM is a cost-effective option for non-critical components, and PTFE is suitable for lightweight seals and liners in low-stress areas.

Figure 2 - Special parts used for Paradigma Technologies Smallsats
3. Electronics Sector
In the electronics sector, PEEK's high dielectric strength, thermal stability, and dimensional precision make it a preferred choice for connectors, insulators, and high-voltage components. It is also ideal for miniaturized parts in high-performance electronics. POM is suitable for low-cost housings or components, and PTFE is recommended for RF applications or lightweight, low-friction parts like cable liners.

Figure 3 - Specific application engineered by Engmotion for a customer in Electronic Sector
General Conclusion
