Learn with Recreus

Not all flexible filaments or TPU are the same. Did you know that there are many options when choosing this type of material? Do you know how to select the most suitable flexible filament for your project?

In addition, we often come across terms like hardness, Shore hardness, Shore or Shore Hardness, along with a two-digit number like 85, 90, 82, etc., and a letter like A. It is understandable that you wonder what these words mean and how they are related to flexible filament.

To address all these doubts and understand the importance of this concept, you cannot miss this practical post where you will learn to better understand the 'Shore Hardness' parameter and its relevance in determining the elasticity of a flexible filament or TPU. Let's get started...

TPU flexible filament?

A TPU flexible filament is an elastomer material, a type of plastic, to which a series of additives are added and with which elastic parts can be created. Due to its properties, it is often used in many industries, being a very popular material in the fashion / textile sector.

As mentioned above, not all flexible filaments are the same, but within its range there is a wide variety and we can choose the type or level of flexibility or elasticity we want. If we are going to create a very elastic piece, we will need a flexible filament, but that is very elastic, or the other way around, within the range of flexible filament, we may want a piece with some flexibility, but not too much.

What is the ‘shore hardness’ scale?

Therefore, in order to measure or talk about the level of intensity of elasticity or flexibility that we require or need from a flexible filament to create a part, we resort to a measurement and scale that we call "shore hardness".

Thermoplastic elastomers are measured with this scale in Shore A and Shore D according to ISO 868. Shore hardness is a measure of the resistance of a material to penetration by a needle under a defined spring force. It is determined as a number from 0 to 100 on the A or D scales. The higher the number, the greater the hardness. The letter A is used for flexible types and the letter D for rigid types. However, the ranges overlap.

'Shore hardness': is a scale that measures the elastic hardness of materials based on the elastic reaction of the material when an object is dropped on it. It is determined as a number from 0 to 100 on scales A or D. The higher the number, the greater the hardness.

How many scales are there?

Several shore scales defined according to the different properties of the materials are used to measure shore hardness. In total, and according to ASTM D2240-00, there are 12 scales (A, B, C, D, DO, E, M, O, OO, OOO, OOO-S, and R), whose values ​​range from 0 to 100 indicating the hardness of the material.

Shore ‘A’ and Shore ‘D’ Scales

The most convenient scale for measuring thermoplastic elastomer materials (or softer plastics) is the Shore A scale. The D scale is used to measure the hardest. In the image gallery you will see in detail the Shore hardness scale “00”, “A” and “D”, as well as their equivalents. Thus, a material with a Shore 82 hardness on the A scale (such as our Filaflex 82A ‘Original’ flexible filament) is roughly equivalent to a Shore 33 hardness on the D scale. Let’s try another example. Filaflex 70A with Shore 70 hardness on the A scale, would be equivalent on the D scale to a Shore 23.

Table of equivalences between scales A and D

Next, we will see a table of equivalences between the A and D scales regarding all the Shore hardnesses of our flexible filaments from the Filaflex family.

In addition, in this graph we can also see the comparison between the Shore A and D hardness scales.

Relationship: Shore A to Shore D

Shore hardness values of all flexible filaments from the Filaflex family

At Recreus, we use the Shore A hardness scale to classify the flexible filaments in the Filaflex range, which allows us to determine their level of elasticity and know in which applications and/or parts they can be used.

Furthermore, at Recreus, we have the widest and most varied catalog of flexible 3D printing filaments with different Shore hardness values. We not only offer filaments with different elasticities based on their Shore hardness, but we also have special varieties that make them unique and incredible for any 3D printing project. These varieties include conductive properties, additives that help purify the environment, and 100% recycled flexible filaments for more sustainable projects.

Specifically, in the Filaflex family of flexible filaments, you can find the following types of materials based on their Shore hardness:

  • Reciflex. It is a 100% recycled flexible filament with a Shore hardness ranging from 96A to 98A.
  • Filaflex 95A, 'Medium-Flex', semi-flexible, with a Shore hardness of 95A, is a very easy-to-print flexible filament compatible with 100% of 3D printers. It has a 500% *elongation.
  • Filaflex Conductive, with a Shore hardness of 92A, is the conductive TPU filament ideal for manufacturing electrically conductive parts or components and wearable devices.
  • Filaflex SEBS, with a TPE rubber base, is a flexible filament with a Shore hardness of 90A, strong and durable, that can be flexed and bent back to its original shape and withstand impact and fatigue. It is an ideal technical material for any application in the industry, combining the flexibility and durability of the Filaflex range.
  • Filaflex 82A, 'Original', is the star filament of the Filaflex range with a Shore hardness of 82A and a 650% *elongation. It has very good elasticity and is the best-selling flexible filament.
  • Filaflex Purifier. Flexible and elastic TPU filament with a Shore hardness of 82A, which, thanks to its innovative additives, helps mitigate pollution and purify the environment. It absorbs CO2, NOx, and VOCs and converts them into harmless mineral waste through gas mineralization.
  • Filaflex FOAMY, has a Shore hardness of 78A, but thanks to its dynamic foaming technology, it can reach a Shore hardness of 51A. It is an ideal filament for printing elastic and lightweight parts, reducing their weight and density.
  • Filaflex 70A, 'Ultra-Soft', with a Shore hardness of 70A, is a highly elastic filament with a 900% *elongation.
  • Filaflex 60A, 'Pro', with a Shore hardness of 60A, is the most elastic and smooth printable filament in the entire Filaflex range and even in the market of elastic filaments for 3D printing. It has a 950% *elongation.

*Elongation: It is the percentage of stretching until the material breaks, as long as its elastic limit is not exceeded.

Elongation of filaments of the Filaflex family

Pack of samples of the Filaflex family. Test all the hardness of the range!

Due to the wide demand and curiosity to test the hardness of Filaflex, we created the sample pack of the Filaflex family. A pack that you have available in our online store in both diameters, both 1.75 mm and 2.85 mm and that includes a sample of 50 gr of each filament of the Filaflex family:

  • 1 sample of Filaflex 95A (black color)
  • 1 sample of Filaflex 82A (grey color)
  • 1 sample of Filaflex 70A (transparent color)
  • 1 sample of Filaflex 60A (white color)

It is the perfect product so that you can test the entire range of Filaflex without having to assume the cost of a larger coil to test with your printer. Below you have more information about ‘Filaflex Family Pack’.

Now that you know what ‘Shore hardness’ means, what Filaflex hardness do you want to print?

Discover the entire range of flexible filaments from Filaflex and enhance your printing experience

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0 Review(s) 


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3 Review(s) 
Recycled TPU filament, 100% from recycled origin. Very easy to print! Shore hardness 96A-98A 100% recycled Made in the EU

Filaflex 95A

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1 Review(s) 
The TPU filament Filaflex 95A, 'Medium-Flex', is the perfect flexible filament for beginners in flexible printing. It is a semi-flexible filament, compatible with all 3D printers on the market, including bowden-type extruder printers (with tube).. Shore hardness 95A 500% stretch Medium elasticity Compatible with all printers Resistant to solvents and...

Conductive Filaflex

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2 Review(s) 
Conductive Filaflex TPU filament is an electrically conductive flexible filament, ideal for manufacturing electrically conductive parts or components and for creating wearable devices. Shore hardness 92A Flexible and conductive Made in the EU

Filaflex SEBS

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0 Review(s) 
TPE filament Filaflex SEBS by Recreus is a rubber-based 3D printing filament that combines Filaflex's flexibility and durability with other properties such as insulation, waterproofness and chemical and thermal resistance. In addition, the filament produces a magnificent final finish of the part and a wide range of uses and applications in the industrial...

Filaflex Purifier

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0 Review(s) 
TPU filament Filaflex Purifier is a flexible filament of Filaflex range for 3D printing, which due to the use of the most innovative additives helps mitigate pollution and purify the environment by adsorbing CO2, NOx and VOCs and converting them into harmless mineral waste through gas mineralisation. A sustainable filament designed to help reduce CO2 and...

Filaflex Foamy

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1 Review(s) 
Filaflex Foamy is a flexible TPU filament that uses dynamic foaming technology to print lightweight elastic parts with reduced weight and density, which allows for increased performance and productivity of the filament spool. Flexible TPU filament Elastic and lightweight parts Shore hardness from 78A to 51A Dynamic foaming technology Weight and density...

Filaflex 70A

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7 Review(s) 
TPU Filament Filaflex 70A, 'Ultra-Soft', is a highly elastic and advanced filament from the Filaflex range for 3D printers. Shore hardness 70A 900% stretch Very high elasticity Resistant to solvents and fuel Odourless No hotbed required Made in the EU

Filaflex 60A

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5 Review(s) 
TPU Filament Filaflex 60A 'PRO' is the most elastic and flexible filament on the market for 3d printers. This filament is only suitable for the most experienced and daring 3d printing enthusiasts using flexible fialments. Shore hardness 60A 950% stretch Extremely elastic Resistant to solvents and fuel Odourless No hotbed required Made in the EU