Plastic Material Selection Guide for Injection Molding
Choosing the right plastic is the most important decision in injection molding. The best material balances mechanical strength, temperature and chemical resistance, cost and appearance. This guide covers the most common injection molding resins and where each one fits.
Common injection molding materials
| Material | Key properties | Typical uses |
|---|---|---|
| PA (Nylon) | Strong, tough, heat & wear resistant | Automotive parts, gears, bushings, clips |
| POM (Acetal) | Stiff, low friction, dimensionally stable | Precision gears, bearings, mechanical parts |
| PC (Polycarbonate) | Impact resistant, clear, heat resistant | Housings, covers, transparent parts |
| ABS | Rigid, tough, easy to finish | Enclosures, cosmetic and consumer parts |
| PP (Polypropylene) | Chemical resistant, flexible, low cost | Living hinges, containers, general parts |
| PBT | Stiff, electrical & heat resistant | Electrical connectors, housings |
| TPE / TPU | Soft, flexible, grippy | Over molded grips, seals, gaskets |
Best plastic for electrical housings
Electrical housings usually call for ABS or polycarbonate for toughness and finish, or flame-retardant PA and PBT grades (UL94 V-0) where fire safety and heat resistance matter. Glass-filled grades add strength and dimensional stability.
PA66 vs POM: which for automotive parts?
- PA66 (nylon): higher strength and heat resistance — good for structural and under-hood parts
- POM (acetal): lower friction and better dimensional stability — good for gears, clips and moving parts
- Choice depends on load, temperature, friction and cost
Glass-filled grades
Adding glass fibre (e.g. 30% GF nylon) significantly increases strength, stiffness and heat resistance, at the cost of higher tool wear and a rougher surface. It's widely used for structural automotive and engineering parts.
Get material advice for your part
Rollex Industries helps customers select the right resin and grade for each application, balancing performance and cost. Contact us with your part requirements.
Frequently Asked Questions
What is the most common injection molding plastic?
Polypropylene (PP), ABS and nylon (PA) are among the most widely used, each suited to different strength, cost and appearance needs.
What plastic is best for electrical parts?
ABS and polycarbonate are common; flame-retardant PA and PBT (UL94 V-0) are used where fire safety and heat resistance are required.
Can Rollex recommend a material for my part?
Yes. Rollex advises on material and grade selection as part of its DFM support for every project.
Need help choosing a material?
Tell us about your part's loads, environment and volume and we'll recommend the right resin.
Contact Rollex Industries