Mechanical Properties of Plastic Materials | The Definitive Guide

mechanical properties of plastics

Plastic material properties, especially plastic mechanical properties, are extremely important for any plastic professional wanted to make quality products. Let’s dive into the article, talking about this in detail.

What are the Mechanical Properties of Plastic Materials?

Hello people, Today, we’ll be looking at the mechanical properties of all mainstream plastic materials. Below is the easiest bifurcation of all mechanical properties possessed by plastics.

Materials Tensile Strength Tensile Elongation Compression Strength Tensile Modulus of Elasticity Flexural Strength Flexural Modulus of Elasticity Hardness Izod Impact
ASTM TEST psi D638, 73°F % D638, 73°F psi D695, 73°F psi D638, 73°F psi D790, 73°F psi D790, 73°F Scales – D785, D2240, 73°F
ft-lbs/in D256, 73°F
ABS 4100 32 294,000 9100 304,000 R102 7.7
Acetal 10000 75 450,000 14300 420,000 M89, R121, Shore D 83 1.5
Acrylic 10000 4.5 17,000 400,000 17,000 480,000 M95 0.4
CAB – cellulose acetate butyrate 5,221 33.9 400,000 230,000 4.4
CE – Canvas Phenolic 9,000 34,000 15,000 1,500,000 M100 1.5
Polyamide 12,400 90 470,000 17,000 410,000 M85, R121, Shore D 80 1.2
ECTFE – Ethylene Chlorotrifluoroethylene 8,000 300 250,000 145,000 Shore D 73 No breaking
HDPE 4,000 600 30,000 200,000 Shore D 69
PBT 8,690 300 416,000 12,000 330,000 M72 1.5
PEEK 14,000 60 400,000 24,600 590,000 M105, R126, Shore D 85 1.6
PET 11,500 70 400,000 15,000 M93, R125, Shore D 87 0.7
PETG 7,700 210 320,000 11,200 310,000 R115 1.7
Polycarbonate 9,500 135 12,500 345,000 135,000 345,000 M70, R118, Shore D 80 12.0 – 16.0
Polypropylene 5,400 225,000 Shore D 75 1.2
PTFE 2,500 150 72,000 Shore D 55 3.5
PVC 7,500 411,000 12,800 481,000 R115, Shore D 89 1
PVDF 7,800 35 350,000 10,750 310,000 M75, R84, Shore D 77 3
TPE 1,740 31
UNMW 3,100 350 110,000 Shore D 64 *

All the values and technical information mentioned above are for information purposes only. All the values have been figured out after extensive research, but still consulting with your material supplier is advised for accurate figures.

Definition – The meaning of mechanical property is the physical attributes shown by a material upon application of forces.

The Purpose of Mechanical Properties in Plastics

The Purpose Mechanical Properties in Plastics

Mechanical Properties are a crucial part of a product’s integrity. Factors like tensile strength, tensile elongation, compression strength, flexural strength, hardness, and elasticity can improve a product’s quality and applications.

Let’s examine the purpose and importance of some of the above attributes.

Impact Strength

The impact strength in thermoplastics is measured by either Charpy or Izod impact tests. The string method is simple but effective. A rectangular rod is placed in a pendulum at high speed, and the energy absorbed while breaking the sample is measured.

The higher the number, the greater the impact resistance. In certain cases, plastics with high resistance values do not break, resulting in no usability. The test will be repeated serval times with a north made on the sample to obtain details under a more dreadful condition.

The plastics with high impact strength are:

Compressive Strength

Compression strength is measured by applying a constantly increasing force on cubical or cylindrical samples placed between two plates, thereby measuring elongation and pressure.

One important thing to note is that the compression property at break is not always accurate because ductile materials sample tends to deform without clear breakage. Unrestrained deformation under load isn’t a reliable indicator of success in real-life industrial applications.

For those reasons, the compressive street is not determined at the break but at a defined deformation point (Usually 1,2, or 10%).  Another smart move would be to check the test conditions before comparing compression values from different sources.

A reliable method to improve or enhance the compression strength of any thermoplastic polymer is to add carbon fiber or glass fiber reinforcements. However, due to enhancements in creep properties, apparent effects on the load performance are noticeable in the long term rather than the short term (That means patience is the key).

The thermoplastics with impressive compressive strength are:

Engaging Read – Physical Properties of Plastic Materials | The Complete Guide


While there are several methods to measure hardness in a thermoplastic, the most common method used is known as “ball indentation hardness.” A sphere-shaped metallic ball of standard dimensions is pressed into material with a certain force; for a certain amount of time, the residual mark will define the hardness value.

Another method, “Rockwell Hardness testing,” is also popular for determining hardness.

Carbon fiber and glass fiber-filled materials show the highest surface hardness.

The materials exhibiting excellent hardness are:

Tensile and Flexural Strength

Flexural strength for any thermoplastics is yielded through the flexure test. In that test, a sample rectangular or circular is bent until a fracture occurs. The flexural strength represents the highest stress experienced by the material in its moment of yield.

Talking tensile strength is the maximum stress a plastic material can resist while being stretched before breaking. Tensile strength is more important in brittle materials than ductile materials.

Materials showing phenomenon tensile strength are:

Flexural Modulus of Elasticity

Flexural modulus of elasticity means the stress equation applied to the material along the axis of the sample tested and deformation determined on the same axis. It is also called young’s modulus and elastic modulus. The flexural modulus of elasticity is determined using Hooke’s law.

In Hooke’s law, force is applied to an object which extends it and puts on a behavior pattern using a stress-strain curve in the elastic deformation region. The dimensions, such as length and thickness, also play a major role in determining the extension of the force.

Flexural modulus is an important mechanical property for selecting the material, product design, and performance analysis.

  1. To decrease the material costs, look for batch quality and long-term consistency in manufacturing.
  2. To assist the design process.
  3. Handy in selecting materials for various purposes by testing them in different circumstances under different types of forces.


Below are the frequently asked questions about the mechanical properties of plastic materials. Let’s learn a bit more about the concept.

What are the general properties of polymers?

Its applications decide the general properties of any polymer. Toughness, reliance, high strength, modulus-to-weight ratios, corrosion resistance, electrical conductivity, and transparency are general properties of plastics.

What are the most important mechanical properties of plastics used in construction?

Tensile and flexural strength is the most important mechanical properties.

Which plastic material has the highest Young’s modulus?

EVOH – Ethylene Vinyl Alcohol – has the highest young’s modulus.

What makes mechanical properties so important for any material?

If determined correctly, mechanical properties can help the product’s design process and decrease material costs with more valuable and quality manufacturing.

Which is the strongest plastic?

Polycarbonate is the strongest plastic on the market. It is 200 times stronger than plastics and crack-free.

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Final Thoughts 

That was all I had to say about the mechanical properties of plastics. I believe determining the right mechanical properties is a must for any plastic manufacturer to cure out the supreme quality of products.

Kindly comment your reviews ad thoughts in the comment box

Have a wonderful day.

1 thought on “Mechanical Properties of Plastic Materials | The Definitive Guide”

  1. I’m trying to fix a mechanical oven push button that has snapped. It is behind the temperature screen that controls an in increase in temperature. I have Gorrilla Glue which is not recommended for polypropelene , polyethelene, bitumen. How do I determine what it is made of? Believe it or not I melted a piece of tube I cut from a cheap giveaway ballpoint pen. I suspect it is made from one of these plastics not recommended by Gorrila Glue.


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