Understanding the Different Types of Plastics Used in CNC Machining

CNC machining can provide many benefits when creating products and parts. However, the type of material you choose can significantly impact the performance, durability, and cost of your final product. As specialists in precision CNC machining for plastics, we can provide help and advice on selecting the right type of plastic for your component or product. Considering the plastic’s characteristics and traits to make sure the material is suitable for your specific application. Whether it’s chemical resistance, strength, temperature tolerance, or machinability.

In this blog, we’ll walk you through some of the most commonly used plastics for CNC machining, helping you understand their properties and how they might fit your next project.

 

Common Plastics Used in CNC Machining

Through our years of experience, we’ve machined a wide range of engineering plastics throughout the years. Here’s a closer look at some of the most used plastics, their benefits, common applications, and some advice to help you choose the right plastic for CNC machining.

Acetal (POM/Delrin®)

Benefits: Excellent dimensional stability, low friction, high strength, and good wear resistance.
Applications: Gears, bearings, bushings, valve components, and other precision mechanical parts.
Choosing Acetal:

• Best for: Projects requiring tight tolerances and smooth, low-friction surfaces.
• Strength: High mechanical strength.
• Heat Resistance: Moderate (up to ~100°C continuous).
• Machinability: Excellent – one of the easiest plastics to machine.
• Cost: Moderate – more affordable than high-performance plastics but more expensive than basic polymers.

View more about Acetal Machining

Nylon (PA)

Benefits: Tough, impact-resistant, good wear resistance, and lightweight.
Applications: Pulleys, spacers, wear strips, gears, and structural components.
Choosing Nylon:

• Best for: High-wear applications where strength and durability are key.
• Strength: Very strong with good fatigue resistance.
• Heat Resistance: Moderate to high (depending on grade).
• Machinability: Good, but can absorb moisture which may affect precision.
• Cost: Affordable – a good balance of performance and price.

View more about Nylon Machining

Polycarbonate (PC)

Benefits: High impact resistance, good optical clarity, and good temperature tolerance.
Applications: Machine guards, transparent enclosures, safety lenses, and light covers.
Choosing Polycarbonate:

• Best for: Projects requiring clarity and toughness.
• Strength: Excellent impact resistance.
• Heat Resistance: High (up to ~135°C continuous).
• Machinability: Good – care is needed to avoid surface marks.
• Cost: Higher than acrylic but offers better durability.

View more about Polycarbonate Machining

Polyethylene (HDPE / UHMW)

Benefits: Excellent abrasion resistance, chemical resistance, and low moisture absorption.
Applications: Chute liners, cutting boards, fluid tanks, and food-safe components.
Choosing Polyethylene:

• Best for: Applications needing chemical resistance or low friction.
• Strength: Moderate, but very tough (especially UHMW).
• Heat Resistance: Lower (HDPE up to ~80°C, UHMW slightly higher).
• Machinability: UHMW is more difficult due to softness; HDPE is easier.

Cost: Very economical, especially in bulk.

PTFE (Teflon®)

Benefits: Extremely low friction, high chemical resistance, and wide temperature range.
Applications: Seals, gaskets, insulation, and components in chemically harsh or high-temperature environments.
Choosing PTFE:

• Best for: Non-stick, chemically resistant, or high-temperature parts.
• Strength: Low mechanical strength, but great stability.
• Heat Resistance: Very high (up to ~260°C continuous).
• Machinability: Soft and slippery – can be tricky but manageable with experience and the right equipment/tooling.
• Cost: Higher due to its specialised properties.

View more about PTFE Machining

PVC (Polyvinyl Chloride)

Benefits: Chemically resistant, flame retardant, and easy to machine.
Applications: Fluid-handling components, enclosures, fittings, and covers.
Choosing PVC:

• Best for: Chemical applications or projects requiring flame resistance.
• Strength: Moderate with good stiffness.
• Heat Resistance: Moderate (up to ~60°C continuous).
• Machinability: Very good – clean cuts and minimal tool wear.
• Cost: Very economical and widely available.

Acrylic (PMMA)

Benefits: High clarity, UV resistance, and a clean, glossy finish.
Applications: Displays, signage, point-of-sale items, guards, and decorative panels.
Choosing Acrylic:

• Best for: Visual appeal and clarity.
• Strength: Brittle under impact but strong under compression.
• Heat Resistance: Lower (~80°C max).
• Machinability: Excellent – machines cleanly but can chip if not handled carefully.
• Cost: Affordable – cheaper than polycarbonate but more brittle.

View more about Acrylic Machining

Ready to bring your project to life?

Choosing the right plastic is crucial to the success of your next project. CNC machining offers many benefits with a wide range of plastic materials available—each with unique strengths—it’s important to match the plastic to your specific performance and budget needs.
Contact our team today to speak for expert advice and begin your project using expertly CNC machined plastic parts. Request a Quote or give us a call—we’re here to help!

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