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In the world of flexible filaments, we often hear or read the word “hardness”, “shore hardness” or “shore” or even appreciate a two-digit number, type “85”, “90”, “82”, etc. along with a letter, such as “A”. It is normal that you are wondering what this all means and what it has to do with the filament.

To solve all these doubts and to be clear about the relevance of this concept, you cannot miss this practical post below with which you will learn to know and better understand how the range of flexible filaments works and their properties. Let’s start…

What is the ‘shore hardness’ scale?

In order to classify the elasticity and flexibility of a material, we resorted to a measurement and scale that we call 'shore hardness'. Thermoplastic Elastomers are measured in Shore A and Shore D according to ISO 868. Shore hardness is a measure of the resistance of a material to the penetration of a needle under a defined spring force. It is determined as a number from 0 to 100 on the scales A or D. The higher the number, the higher the hardness. The letter A is used for flexible types and the letter D for rigid types. Though, the ranges do overlap. This chart shows a comparison of the Shore hardness A and D scales for Apilon 52 TPU materials. Shore hardness reduces as temperature rises.

'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

Now, we are going to see a table of equivalences between the A and D scales referring to the 4 Shore hardnesses of our Filaflex filaments.

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

The Shore hardnesses of the Filaflex family

At Recreus we use the Shore A hardness scale to classify the flexible filaments of the Filaflex range. In this way, we determine the hardness of each filament to know in which applications and/or pieces we can use it based on its Shore hardness (elasticity).

Specifically, in the Filaflex family we have 4 types of filament according to their Shore hardness:

  • Filaflex 95A, ‘Medium-Flex’, semiflexible, with Shore hardness of 95A, very easy to print and compatible with the 100% of the 3d printers. With 500% of *elongation.
  • Filaflex 82A, ’Original’ and our flagship filament in the Filaflex range. With a Shore hardness of 82A. Very good elasticity and the best selling flexible filament. It has an elongation of 650%.
  • Filaflex 70A, ‘Ultra-Soft’, with a Shore hardness of 70A, is a highly elastic and advanced filament with an *elongation of 900%.
  • Filaflex 60A, 'Pro', with a Shore hardness of 60A, is the most elastic and softest filament in the entire Filaflex range and even in the elastic filament market for 3D printing. Has an *elongation of 950%.

*Elongation is the percentage of stretch 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 Filaflex

Filaflex Family Pack

Discover all the printing possibilities with the complete Filaflex range. With the sample pack of the entire Filaflex family, you will be able to test all Shore hardnesses (60A, 70A, 82A and 95A) of our star elastic filament brand, and thus check which of them best suits your project or application. Resistant to solvents, fuel and acetone Odourless No...
€12.31

Filaflex 95A

Filaflex 95A, ’Medium-Flex’, is the perfect filament for beginners in flexible printing. It's a semi-flexible elastic filament, compatible with all 3D printers on the market, including those with a Bowden extruder (with tube). Shore hardness 95A 500% stretch Medium elasticity Compatible with all printers Resistant to solvents, fuel and acetone Odourless...
€27.90

Filaflex 70A

Filaflex 70A, ’Ultra-Soft’, is a highly elastic and advanced filament from the Filaflex range for 3D printers. Shore hardness 70A 900% stretch High elasticity Resistant to solvents, fuel and acetone Odourless No hotbed required Made in the EU
€37.90

Filaflex 60A

Filaflex 60A 'PRO', the most elastic and flexible filament on the market, only suitable for the most 'pro' and intrepid of flexible filament printing. Shore hardness 60A 950% stretch High elasticity Resistant to solvents, fuel and acetone Odourless No hotbed required Made in the EU
€41.24