When 3D-printed parts need maximum strength, factors that matter include 3D printer settings, part orientation, and material choice.
While each factor is critical to strength, material choice is arguably the most important because it defines the part’s mechanical characteristics.
Choosing the strongest 3D printing material requires delving into technical data sheets to compare filaments and working with uncommon engineering materials that are harder to print than ABS and PLA.
This article provides five tips to choose the strongest 3D printing material, starting with the most overlooked aspect of all: strength requirements.
Define your strength requirements
Generalised statements like “the strongest 3D printing filament” are unhelpful when you realise that strength is a relative term.
For example, tensile strength, impact strength, and flexural strength are different properties. A filament with exceptional impact strength might have terrible flexural strength and vice versa, skewing your research.
You need to define which of these is the priority:
- Tensile strength is the maximum load a material can support without fracture when pulled. In other words, it is the ability to withstand elongation. For example, a 3D-printed composite chain under load has a tensile force applied to it.
- Impact strength is the amount of energy a material can withstand suddenly applied to it. In other words, it is the resistance to fracture by force. For example, a 3D-printed casing dropped on the floor has an impact force on it.
- Flexural strength is the ability of a material to resist deformation under load. In other words, it specifies the stress at failure in bending. For example, a 3D-printed plastic rod bent over a pipe has a flexural force applied to it.
Knowing what to look for in material properties data is the first step to choosing the best 3D printing material for your parts.
Know your material candidates
Once you know which material properties your parts need, you can start looking at materials based on their general properties.
If you need tensile strength, consider these materials: PEEK and PEKK (with 3DGence machines), Polycarbonate, PET-G, and ABS. Composite materials like fibreglass and carbon fibre (check out Markforged) also work brilliantly.
For impact strength, look at PEEK, nylon, polypropylene (PP), polycarbonate, and PLA. However, for flexible impact strength, TPU is the best option.
For flexural strength, look at thermoplastic elastomers like TPE, TPU, and TPA. You can also print silicone with Lynxter 3D printers. For solid materials that need flexural strength, check out PLA, Tough PLA, and Nylon without reinforcement.
Read the product data sheets
While knowing your essential filament candidates is useful, it’s crucial to remember that not all 3D printing filaments are created equal.
For example, Ultimaker PC has a tensile strength of 58.7 MPa at break, yet some generic polycarbonates can only muster 50 MPa. The worst filament for wild fluctuations is nylon, which can perform poorly or amazingly.
The bottom line – it pays to read product data sheets because there are variations in mechanical qualities between filament manufacturers.
High-quality filament is only part of the equation
Even if you choose a high-strength, engineering-grade 3D printing material, printer settings and part design largely determine the final part’s strength.
The reality is that an ABS part with an optimal design made with the correct printer settings will outperform a poorly designed PC equivalent.
For example, if you orientate your part in the incorrect position, the layers won’t be built optimally. The critical thing to know is that tension load down on layers exposes weakness, while tension load parallel to layers showcases strength.
Another common problem is incorrect printer settings, especially temperature, with too high or low a temperature impacting the filament’s molecular structure. This can reduce dimensional stability and rigidity.
Don’t make the mistake of using a high-strength material as a crutch – part design and printer settings are equally important.
Consider your skill and 3D printer limitations
While it’s easy to say PEEK, PEKK, Polycarbonate, and composite filaments offer brilliant strength, printing them isn’t always straightforward.
PC can be difficult to print because it is prone to warping and shrinkage, and PEEK and PEKK require an extremely high temperature.
Even ABS – a basic filament for model making – can fail if the 3D printer is not capable of producing the required geometries and infill. While using the correct settings helps, there is always the chance the printer is not up to the job.
Additionally, some 3D printers won’t print nylon and composites so easily. A common problem is brass nozzle wear, with composites (among other abrasive 3D printing materials) requiring stainless-steel nozzles.
Another fly in the ointment is your knowledge and skill, which might need to be improved to work with difficult materials. If you don’t have the luxury of time, using an easier-to-print filament that is slightly weaker might be best.
Choosing the strongest filament comes down to two key factors:
- The type of strength required
- The level of strength required
Cost-per-part is another critical point, with engineering materials like PC and industrial materials like PEEK being more expensive than standard materials like ABS and PLA. You might need to find a compromise if you have a tight budget.
Find out more
For help choosing a filament or to find out more about the 3D printing materials listed in this article, please get in touch with the team at 01765 694 007, email firstname.lastname@example.org, or you can