Quick3D How to read a technical data sheet (TDS)
A plain-English tour of a 3D-printing material datasheet: what each section means, which test conditions matter and the traps to avoid.
A technical data sheet, or TDS, is the manufacturer’s summary of how a material behaves under controlled tests. It is the most useful single document you have when choosing a material. It is also easy to misread. This guide walks through a typical TDS section by section, explains the small print, and shows how the Quick3D Materials Hub handles the numbers.
Key takeaways
- A datasheet shows how standard specimens performed, not how your part will.
- Most values are typical averages, not minimums or guarantees.
- Check the test standard, specimen type, orientation and post-processing beside each value.
- Watch units: GPa vs MPa, and temperature differences in °F.
What a TDS is, and what it is not
A TDS reports how standard test specimens performed in a lab. Those specimens were made in a specific way, conditioned in a specific way and tested at a specific speed and temperature. Your part will be a different shape, printed on a different machine, with different settings. So a TDS tells you how materials compare under like-for-like conditions. It does not promise how your part will perform.
Keep that in mind and a datasheet becomes a powerful shortlisting tool. Forget it and you can end up designing to a number that never shows up in your part.
The anatomy of a datasheet
Layouts vary between brands, but most sheets for 3D-printing materials contain the same building blocks.
General information
The base polymer (PLA, PETG, PA12, a photopolymer resin), any reinforcement such as carbon or glass fibre, the form (filament, resin, powder or pellets), colours and spool or bottle sizes. Density often lives here too. Read the reinforcement line carefully: a filled grade behaves very differently from the unfilled one.
Mechanical properties
Usually the longest section. Expect tensile strength, Young’s (tensile) modulus, elongation at break, flexural (bending) strength and modulus, and impact strength. Flexible materials add hardness on the Shore scale and sometimes tear strength.
To give you a sense of scale, the filaments in our catalog report tensile strengths of 8–1,540 MPa (median 52.3 MPa, 259 materials), and resins report 1.1–91 MPa (median 44 MPa, 203 materials). Both spans are wide because they cover everything from soft elastomers to fibre-filled engineering grades.
- PLA 3118–56
- PETG 1717.9–105
- ABS 2024.3–68
- TPU 198–60
- PA12 1033.4–120
- PC 1236.1–73
- PEEK 1370–145
Bar = lowest to highest, dot = median. 122 materials, live from our database.
Thermal properties
Heat deflection temperature (HDT), glass transition temperature (Tg), Vicat softening temperature and, for semi-crystalline polymers, melting temperature. These answer the question “when does it get soft?” in slightly different ways. HDT is the one people quote most, and the one most often misread. See HDT at 0.45 MPa vs 1.8 MPa.
Electrical properties
Surface or volume resistivity, dielectric strength and sometimes dielectric constant. These matter for ESD-safe parts, enclosures and insulators. Many standard materials leave this section blank.
Chemical and other properties
Resistance to acids, alkalis, oils and solvents, often as a simple rating. Flammability ratings such as UL 94, water absorption, UV resistance and any certifications sit here too. Certifications apply to a specific grade and, often, a specific process. They do not transfer automatically to your printed part.
Print and processing settings
Nozzle and bed temperatures, print speed, drying conditions, cooling, or exposure times and post-cure schedules for resins. These are not just advice. They are usually the conditions under which the test specimens were made, so they are part of the context for every number above.
What “typical value” means
Most 3D-printing datasheets report typical values: an average from a set of test specimens. Half the specimens may have come in below it. A typical value is not a minimum and not a guarantee. Some sheets add a ± figure to show the scatter. A few industrial grades publish minimum or specification values instead. The difference matters a lot when you design a load-bearing part. Read typical vs minimum values for more.
Test standards: the code next to the number
Every serious datasheet names the test method beside each value, such as ISO 527 or ASTM D638 for tensile properties. That code tells you the specimen shape, the test speed and how the result was calculated. Two values measured to different standards are related, but they are not interchangeable. Our guide to ASTM vs ISO test methods covers the common pairs.
Watch out
If a value has no method at all, treat it with caution. You cannot tell how it was obtained.
Specimen type and orientation
For printed materials, how the specimen was made is as important as the standard. Look for answers to these questions:
- Printed or moulded? Some filament sheets report values from injection-moulded bars of the raw polymer. Those describe the plastic, not a printed part, and usually look better.
- Which orientation? FFF parts are weaker across their layers than along them. A sheet may give XY values only, or XY and Z values side by side.
- Which infill and wall settings? Test specimens are usually printed solid. A part with sparse infill will not match.
- Which post-processing? Annealing, UV post-cure and thermal post-cure can all change results.
See print orientation: XY vs Z for how to read orientation labels.
Units and conversions to watch
| Quantity | Common units | Conversion |
|---|---|---|
| Strength (stress) | MPa, psi, ksi | 1 MPa ≈ 145 psi; 1 ksi = 1,000 psi ≈ 6.9 MPa |
| Modulus (stiffness) | MPa, GPa, ksi | 1 GPa = 1,000 MPa |
| Temperature | °C, °F | °F = °C × 9/5 + 32 |
| Density | g/cm³ | 1 g/cm³ = 1,000 kg/m³ |
| Impact (Charpy) | kJ/m² | Energy per area of the cross-section |
| Impact (Izod) | J/m, ft·lb/in | Energy per width; not convertible to kJ/m² |
Watch out
Two traps catch people often. First, modulus in GPa next to strength in MPa: a modulus of “2.1” and a strength of “50” are not on the same scale. Second, temperature differences. A 10 °C gap is an 18 °F gap, not a 50 °F one, because you only scale differences, you do not add 32.
Common traps
- Comparing different loads for HDT. A value at 0.45 MPa will be higher than one at 1.8 MPa for the same material.
- Yield vs break. Tensile strength can be quoted at yield or at break. For ductile plastics these differ.
- Dry vs conditioned. Nylons absorb moisture. Dry specimens are stiffer and stronger; conditioned ones are tougher and more flexible.
- Green vs post-cured resin. Resin properties depend heavily on the cure schedule used.
- Old sheets. Formulations change. Check the revision date and use the current sheet.
- Missing values. A blank does not mean poor performance. It usually just means the test was not run.
How the Quick3D Materials Hub normalises data
We want the hub to be faithful to the source, so we change as little as possible:
- Values are copied as printed from the manufacturer’s official datasheet. We do not adjust, average or estimate.
- GPa is converted exactly to MPa so every modulus sits on one scale. No rounding beyond the original precision.
- Ranges are shown as printed. If a sheet gives a range, you see the range.
- Conditions are noted. When a sheet gives several conditions, such as two HDT loads, dry and conditioned, or XY and Z, we note which one we show, next to the test method.
The hub’s ranges and charts pool values from many sheets. That is ideal for getting a feel for a material family. For a final decision, open the individual material pages and check the method and condition beside each value, then read the linked TDS.
Go deeper
- Typical vs minimum values
- ASTM vs ISO test methods
- Print orientation: XY vs Z
- HDT at 0.45 MPa vs 1.8 MPa
- Shore A vs Shore D
- Comparing materials across brands
Browse filaments and their datasheets