Choosing High-Performance Polymers for Critical Vehicle Parts
When designing vehicle components, selecting the right plastic is more than a design choice – it’s a decision that impacts safety, reliability, and manufacturing efficiency. With the rise of light weighting, electrification, and complex part geometries, automotive plastic injection moulding has become the go-to manufacturing method for engineers seeking precision and repeatability at scale.
At Stephens Plastic Mouldings, we’ve supported leading automotive OEMs and Tier 1 suppliers across the UK by delivering expertly moulded parts made from materials that meet or exceed global performance standards.
The Top Plastics Used in Automotive Injection Moulding
1. Glass-Filled Nylon (PA66-GF)
Favoured for its high tensile strength, thermal stability, and resistance to fuels and lubricants, glass-filled nylon is ideal for:
- Under-hood components.
- Engine mounts.
- Brake and clutch parts.
Its dimensional stability under heat and stress makes it a trusted material in modern combustion and electric vehicles.
2. Acetal (POM)
Known for low friction, chemical resistance, and exceptional dimensional precision, acetal is used for:
- Door handles.
- Fuel system parts.
- Interior gears and fasteners.
3. Polypropylene (PP)
Lightweight and versatile, PP is suitable for interior trims, battery casings, and aesthetic features. It’s valued for its impact resistance and recyclability – helping car manufacturers meet sustainability goals.
4. ABS (Acrylonitrile Butadiene Styrene)
For aesthetic parts that need strength and a smooth finish, ABS is unmatched. Often used in dashboards, consoles, and interior housings, ABS balances form with function.
Material Selection Isn’t Just Technical – It’s Strategic
Beyond tensile strength or thermal limits, selecting the right automotive plastic comes down to:
- Assembly compatibility (snap fits, welds, inserts).
- Regulatory compliance (flammability, VOCs, REACH).
- Tooling cost vs longevity.
- Projected production volume.
Stephens Plastic’s engineers review every design with these in mind. Our in-house tooling team and trial tool process allow you to validate your chosen material quickly and affordably – before full-scale production begins.
Why Stephens Plastic Is the Go-To UK Partner for Automotive Projects
1. Decades of Industry Experience
From prototype to production, we understand the demands of global automotive supply chains.
2. Advanced Machinery
25T to 470T machines deliver tight-tolerance parts in volumes from hundreds to hundreds of thousands.
3. Material Consultancy
We recommend the right polymer based on mechanical performance, cost, and production efficiency.
4. Full UK-Based Service
Design, tooling, moulding, post-processing, packaging – all done in the UK, with faster lead times and no import delays.
FAQs
1. What is the best plastic for under-the-hood automotive components?
Glass-filled nylon (PA66-GF) is widely used due to its high temperature resistance, strength, and durability in demanding environments.
2. Can Stephens Plastic help me choose the right polymer for my car part design?
Yes. Our engineering team offers design for manufacture (DFM) reviews to match the best plastic to your mechanical, chemical, and thermal requirements.
3. Do you offer low-volume automotive moulding for pre-production parts?
Absolutely. We specialise in low-volume and bridge tooling projects to support prototyping and market validation before ramping up production.
4. Are your moulded parts compliant with automotive standards?
Yes. We follow ISO 9001:2015 protocols and use automotive-grade polymers that meet REACH, RoHS, and other industry standards.
5. How quickly can I get sample parts or prototypes?
With in-house tooling and dedicated project management, we can often deliver first-off parts within 2-4 weeks depending on complexity.
Speak to Our Automotive Plastics Team Today
Need help choosing the best material for your injection moulded part?
Want to compare glass-filled nylon vs acetal in a specific application?
Contact Stephens Plastics Today
Email: enquiries@stephensplastics.co.uk
Phone: 0121 544 5808
To get expert guidance and a no-obligation quote from our automotive plastics specialists.