CNC Machining Plastic materials

We provide instant quotes for more than 200 kinds of plastic and compare the prices of different processing materials for you.

ABS

ABS is a copolymer made up of three monomers: acrylonitrile, butadiene, and styrene. The combination of these monomers provides ABS with a unique set of properties, including high impact resistance, good heat resistance, and excellent dimensional stability.

Mechanical properties
Ultimate tensile strength	27.6 – 55.2 MPa
Yield strength	18.5 – 51 MPa
Young’s modulus	1.1 – 2.9 GPa
Elongation at break	10 – 50 %
Hardness	5.6 – 15.3 HV

Thermal properties
Maximum service temperature	61.9 – 76.9 °C
Thermal expansion coefficent	84.6 – 234 10^-6/ºC
Thermal conductivity	0.188 – 0.335 W/(m⋅°C)

PMMA

PMMA also known as acrylic, is a tough and transparent material that resists UV radiation and weather. It can be easily colored, shaped, and used for various applications in construction due to its attractive appearance.

Mechanical properties
Ultimate tensile strength	55 – 83 MPa
Yield strength	64 -80 MPa
Young’s modulus	2.76 – 3.3 GPa
Elongation at break	3 – 6.4 %
Hardness	64 – 105 HRM

Thermal properties
Maximum service temperature	70 – 80 °C
Thermal expansion coefficent	50 – 90 10^-6/ºC
Thermal conductivity	0.19 – 0.2 W/(m⋅°C)

PE

PE (Polyethylene) is a popular thermoplastic polymer known for its exceptional properties. This lightweight, durable, and versatile material is widely used in various applications, as it can be easily processed into different shapes and sizes.

Subtypes	Ultimate tensile strength	Yield strength	Young’s modulus	Elongation at break	Hardness
HDPE	22.1 – 31 MPa	26.2 – 31 MPa	1.07 – 1.09 GPa	500 – 700 %	7.9 – 9.9 HV
UHMW-PE	38.6 – 48.3 MPa	21.4 – 27.6 MPa	0.894 – 0.963 GPa	200 – 500 %	3.4 – 8.3 HV

Nylon

Nylon, a synthetic thermoplastic polymer, requires careful consideration during machining to avoid overheating, which can lead to issues like melting, warping, or damage.

Subtypes	Ultimate tensile strength	Yield strength	Young’s modulus	Elongation at break	Hardness
Nylon 6	64.7 – 79.1 MPa	51.2 – 63.8 MPa	1.58 – 1.97 GPa	200-300 %	Shore D70
Nylon 6 30% GF	113 – 138.1 MPa	111 – 137 MPa	6.5 – 8.1 GPa	2.81 – 4.05 %	Shore D92
Nylon 66 30% GF	90 MPa	90 MPa	5 GPa	10 – 14 %	Shore D76
Nylon 6 FR	82 MPa	82 MPa	3.8 GPa	3 %	Shore D83
Nylon 12	80 MPa	80 MPa	1.9 GPa	200%	Shore D78
Nylon 66	76 MPa	50 – 80 MPa	1.85 GPa	50%	Shore D82

PEEK

PEEK (Polyetheretherketone) is a unique engineering plastic known for its outstanding properties, including high-temperature resistance, self-lubrication, ease of processing, and exceptional mechanical strength.

Mechanical properties
Ultimate tensile strength	70.3 – 103 MPa
Yield strength	87 – 95 MPa
Young’s modulus	3.76 – 3.95 GPa
Elongation at break	30 – 150 %
Hardness	26.1 – 28.5 HV

Thermal properties
Maximum service temperature	239 – 260 °C
Thermal expansion coefficent	50 – 60 10^-6/ºC
Thermal conductivity	0.24 – 0.26 W/(m⋅°C)

PC

Polycarbonate is a strong and tough plastic with flame retardant and antioxidant properties. It has excellent impact strength, transparency, and mechanical properties.

Mechanical properties
Ultimate tensile strength	60 – 72.4 MPa
Yield strength	59- 70 MPa
Young’s modulus	2 – 2.44 GPa
Elongation at break	50 – 120 %
Hardness	17.7 – 21.7 HV

Thermal properties
Maximum service temperature	101 – 144 °C
Thermal expansion coefficent	120 – 137 10^-6/ºC
Thermal conductivity	0.189 – 0.218 W/(m⋅°C)

PP

PP (Polypropylene) boasts remarkable chemical resistance, a high melting point, and low density. When machining PP using CNC, it’s crucial to use a sharp cutter with a high front angle and a low cutting speed. These measures prevent the material from overheating and melting.

Subtypes	Ultimate tensile strength	Yield strength	Young’s modulus	Elongation at break	Hardness
PP Homopolymer		19 – 30 MPa	0.7 – 1.2 GPa	min. 50 %
PP	23 – 33 MPa	30 – 32 MPa	0.9 – 1.6 GPa	8 – 12 %	65 – 102 HRR
PP+GF(30%)	68 – 85 MPa		6.5 – 7 GPa	2.1 – 3.4 %	110 HRC

PET

Polyethylene terephthalate (PET), a thermoplastic material, is a viable option for CNC milling and lathing processes due to its good machinability and versatility. With proper tooling and cutting parameters, PET can be easily shaped and formed, making it ideal for creating prototypes, custom parts, and containers through CNC machining.

Mechanical properties
Ultimate tensile strength	50 – 90 MPa
Yield strength	47 – 90 MPa
Young’s modulus	2 – 3 GPa
Elongation at break	20 – 300 %
Hardness	80 – 96 HRM

Thermal properties
Maximum service temperature	60 – 115 °C
Thermal expansion coefficent	40 – 60 10^-6/ºC
Thermal conductivity	0.15 – 0.28 W/(m⋅°C)

PEI

PEI (Polyetherimide) is a tough and durable material known for its high melting point and abrasive characteristics. By utilizing specialized cutting tools and techniques, it can be effectively cut and shaped to produce high-quality parts with precise tolerances.

Subtypes	Ultimate tensile strength	Yield strength	Young’s modulus	Elongation at break	Maximum service temperature
PEI Ultem 1000	125 MPa	125 MPa	3.1 – 3.3 GPa	12 – 35 %	170 °C
PEI Ultem 2300 30% Glass Filled	135 MPa	135 MPa	5.3 GPa	4 %	170 °C

POM

POM (Polyoxymethylene) is a thermoplastic material renowned for its high stiffness, low friction, easy cutting, and excellent dimensional stability. However, machining POM can be challenging due to its high melting point and susceptibility to chipping or cracking if the cutting parameters are not carefully controlled.

Subtypes	Ultimate tensile strength	Yield strength	Young’s modulus	Elongation at break
Acetal Copolymer(POM-C)	60 – 70 MPa	60 – 67 MPa	2.5 – 2.7 GPa	30 – 32 %
Acetal Copolymer (POM-C) FDA	70 MPa	66 – 70 MPa	2.8 – 3 GPa	32 – 40 %
Acetal Homopolymer (POM-H)	60 – 89.6 MPa	48.6 – 72.4 MPa	2.5 – 4 GPa	15 – 75 %
Acetal Copolymer (POM-C) ESD	39 MPa	45 MPa	2.5 – 2.7 GPa	40 – 50 %

PVC

PVC is strong, durable, and resistant to chemicals, weather, and fire. However, machining it can create harmful dust and fumes that may be unsafe for workers. To keep workers safe, use proper safety equipment and ventilation during the process.

Mechanical properties
Ultimate tensile strength	46 – 58 MPa
Yield strength	53 – 58 MPa
Young’s modulus	2.18 – 3.41 GPa
Elongation at break	25 – 80 %
Hardness	13.7 – 16.6 HV

Thermal properties
Maximum service temperature	85 – 100 °C
Thermal expansion coefficent	112 – 149 10^-6/ºC
Thermal conductivity	0.133 – 0.144 W/(m⋅°C)

PTFE

When machining PTFE, using the right cutting tools is crucial because PTFE has a low friction coefficient, which can lead to overheating and deformation of the tool. To overcome this, carbide cutting tools are commonly employed as they are durable and can withstand heat effectively.

Mechanical properties
Ultimate tensile strength	25 – 31 MPa
Yield strength	14 – 41.4 MPa
Young’s modulus	0.39 – 2.25 GPa
Elongation at break	300 – 450 %
Hardness	50 – 65 Shore D

Thermal properties
Maximum service temperature	250 – 270 °C
Thermal expansion coefficent	7 – 20 10^-6/ºC
Thermal conductivity	0.23 – 0.5 W/(m⋅°C)

How to Make the Right Choice

There are several important elements to take into account when choosing plastic materials for CNC machining to make sure the finished product fulfills your expectations. Here are some factors to take into account when choosing a plastic material:

Mechanical Properties: Select a plastic material with the proper mechanical qualities, such as strength, hardness, and wear resistance, depending on the project’s requirements. ABS, polyurethane, and other popular polymers have good mechanical qualities.

Chemical Resistance: To avoid corrosion or distortion, you must use a plastic material with strong chemical resistance if your parts must come into contact with chemicals. Both polypropylene and polyethylene can withstand chemicals well.

Temperature Resistance: You must select a plastic material that can tolerate the necessary temperature range if your component will be used in a high- or low-temperature environment. For instance, PA66 (nylon 66) is well suited to withstand high temperatures.

Electrical Properties: You may want to use a plastic material with good insulating characteristics, such as polytetrafluoroethylene (PTFE), for applications that call for effective electrical insulation.

Transparency and Color: Choose a transparent or tinted plastic material, like polycarbonate (PC), if you require a specific color or level of transparency for a component.

Cost considerations: The price of various plastic materials will differ, therefore you must choose the best material in accordance with your project budget.

Machinability: Consider the material’s machinability, taking into account its cutting capabilities, abrasion resistance, and ease of shaping into the appropriate shape.

Environmental considerations: With more and more projects focusing on the environment, you can minimize your environmental impact by choosing plastic materials that are recyclable or biodegradable.

Plastic Standard and other

Plastic materials are often regulated and standardized to ensure their safety, quality, and environmental impact. One of the well-known standards organizations that sets standards for plastic materials is the International Organization for Standardization (ISO).

ASTM’s plastics standards

Material Properties of Plastics

PROPERTY COMPARISON CHART FOR PLASTIC MATERIALS

Plastic MATERIAL SELECTION GUIDE

Mechanical Properties of Plastic Materials

Plastics & Composites / Performance : Cost

Other

Materials are an essential basic capability in the industry, and their development can promote technology and innovation and society’s development. The current trend of material development is to be more environmentally friendly and energy-saving.