A technical data sheet, or TDS, is an informational sheet that describes the mechanical properties of a material in detail. For 3D printing, filament manufacturers test their filament and then put that information in a TDS, which can normally be found on their website.

A Technical Data Sheet
From: 3dfuel.com
What Information is on a TDS?
As the name implies, there is a lot of technical information on a TDS. This includes mechanical data, such as strength and toughness specifications, and heat data, which can be beneficial to know when printing.
Mechanical Data
There are a few key data points to look for on a TDS: Tensile Yield Strength, Tensile Elongation, Flexural Modulus, and Flexural Strength. Tensile Yield Strength and Tensile Elongation are usually found near the top of the TDS as they tell you a lot about the filament. Tensile Yield Strength is possibly the most important. This is a measure of the material’s strength and is defined as the amount of pressure that the material can withstand before breaking when being pulled from both ends. Tensile Elongation goes hand in hand with the Yield Strength. This is how much the material stretches before it breaks. Together these give a measure of the filament’s strength and toughness.
In addition to Tensile Strength and Elongation, Flexural Modulus and Strength are also important measures of the material’s strength and toughness. Flexural Modulus measures the amount of pressure required to bend the material. This gives us an accurate reading of how stiff the material is. On the other hand, Flexural Strength is the amount of pressure required for the material to become deformed. This gives us another measure for the strength of the material.
Heat Data
In addition to the mechanical data, heat data is often included on a TDS. The exact heat data that is included varies from sheet to sheet, but there are several data points that are always included. These are the melt temperature and the glass transition temperature of the material. These can assist with printing and annealing the material as well as determining how much heat the 3D printed part can withstand. Other common heat data includes the heat distortion, 3D printing, annealing, and print bed temperatures. These give us more information on the heat parameters of the material. For example, the heat distortion temperature is the temperature at which the material starts to deform. The other heat information is used in printing the material.

3D Fuel TDS Data Table
From: 3dfuel.com
How to Use This Data
Now that we know what data is included on a TDS, we need to know how to use it effectively. If you look at one TDS, the numbers may not mean much on their own. However, the data becomes useful when it is compared between materials. To demonstrate, I have included data from three different TDSs for PLA.

NatureWorks TDS Data Table
From: natureworksllc.com

Ultimaker TDS Mechanical Data Table
From: ultimaker.com
Take a moment to look at the data from each of the tables to the right. If we compare the data, we can determine which of these three filament brands has the best PLA. First, notice that these data points are measured differently. The 3D Fuel and NatureWorks TDSs measure in both psi and Mega Pascals (MPa). However, Ultimaker only uses MPa. Because of this, we will compare using the MPa measure.
We will compare the Tensile Yield Strength first. 3D Fuel has a value of 65.5, NatureWorks has a value of 51, and Ultimaker has a value of 38. Looking at Flexural Strength and Modulus (which is called Tensile Strength and Modulus by NatureWorks) we see that 3D Fuel has values of 126 and 4357 respectively, NatureWorks has values of 50 and 2315, and Ultimaker has values of 65, and 2409. From this, we can see that 3D Fuel’s PLA is both stronger and tougher than NatureWork’s and Ultimaker’s. However, NatureWork’s PLA is slightly stronger than Ultimaker’s, while Ultimaker’s is slightly tougher.
What is This Data Useful For?
The data that a TDS provides is not useful for everyone. Its usefulness depends on what you are printing. If you are just printing for fun on a desktop 3D Printer, then the quality and mechanical properties of your filament will matter less. However, if you are printing something for a specific, practical use that will bear weight or undergo stress, then this data is essential for knowing what filament is best for your specific project.