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Engineering Plastics CNC Machining: PEEK, PEI, POM & Nylon Parts Guide

What is Engineering Plastics Machining?

Engineering plastics combine light weight, electrical insulation, low friction and chemical resistance. We CNC machine high-performance polymers — PEEK, PEI (Ultem), POM (Delrin/acetal), nylon, HDPE, UHMWPE, PSU, PAI (Torlon), polyimide and acrylic — for demanding technical applications.

PEEK and PEI for high performance

PEEK offers high temperature and chemical resistance with excellent mechanical strength for medical, aerospace and industrial parts. PEI (Ultem) is a cost-effective alternative with strong insulation and flame resistance.

POM and nylon for wear

POM (Delrin) provides low friction, dimensional stability and easy machining for gears, guides and precision parts. Nylon is tough and wear-resistant for bushings, rollers and functional components.

Managing plastic behaviour

Plastics expand more than metal and can absorb moisture, so we control temperatures, use sharp tooling and allow for thermal expansion and internal stress to keep parts stable.

Featured Engineering Plastics Machining parts

Every part below is manufactured in-house and available made-to-print. Click through to view materials, specifications and finish options.

PEEK CNC Milled Insulator BlockPEEK CNC Milled Insulator BlockPOM Delrin CNC Milled GearPOM Delrin CNC Milled GearNylon PA CNC Machined BushingNylon PA CNC Machined BushingAcrylic PMMA CNC Milled PanelAcrylic PMMA CNC Milled PanelABS CNC Milled EnclosureABS CNC Milled EnclosureHDPE CNC Machined Guide PlateHDPE CNC Machined Guide PlatePEI Ultem CNC Machined FixturePEI Ultem CNC Machined FixturePAI Torlon CNC Milled Seal RingPAI Torlon CNC Milled Seal RingPI Polyimide CNC Machined WasherPI Polyimide CNC Machined WasherPEEK CNC Machined BracketPEEK CNC Machined BracketPOM Delrin CNC Machined BushingPOM Delrin CNC Machined BushingNylon PA CNC Milled SpacerNylon PA CNC Milled Spacer

Typical applications

Insulators and electrical components, medical and semiconductor equipment, gears and bearings, guides and wear strips, seals and bushings, and lightweight structural parts.

Frequently asked questions

Which engineering plastic should I use?

Choose PEEK for high temperature/strength, PEI for insulation and value, POM for low-friction precision parts, and nylon for tough wear components. We can recommend a grade.

How do you handle plastic thermal expansion?

We account for each material’s expansion and moisture behaviour in fixturing and tolerances, and stress-relieve stock where needed.

What tolerances can plastic parts hold?

Precision polymer parts can hold tight tolerances depending on the material and geometry; we define realistic, part-specific tolerances during DFM.

Can you machine medical-grade plastics?

Yes — including medical-grade PEEK and other biocompatible polymers with appropriate documentation and clean handling.

Request a quote

YOUSU Precision is an ISO 9001 certified manufacturer in Shenzhen. Send your STEP, STP, IGS, DWG or PDF with quantity and finish requirements, and our engineering team responds within 24 hours with DFM feedback, price and lead time — supporting prototype, small-batch and repeat volume production with full inspection documentation.

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