Graphene is often called the strongest material ever tested. In 2008, researchers at Columbia University measured the strength of a single, defect-free sheet and published the results in Science. They found an intrinsic strength of around 130 gigapascals and a stiffness (Young’s modulus) of about 1 terapascal. Weight for weight, that is roughly 200 times stronger than steel.
The material itself was first isolated in the UK, at the University of Manchester, in 2004. Andre Geim and Konstantin Novoselov won the 2010 Nobel Prize in Physics for that work.
So where does all that strength come from?
1. Some of the strongest bonds in nature
Graphene is pure carbon. Each carbon atom is bonded to three neighbours by covalent carbon–carbon bonds, a type known as sp² bonds. These are among the strongest chemical bonds there are, and they are also what hold diamond and carbon fibre together.
2. A perfect honeycomb with no weak points
Those bonds are arranged in a flat hexagonal lattice, like chicken wire. Load spreads evenly across the whole network instead of concentrating at one point. A pristine sheet has no grain boundaries, voids or weak planes where a crack could start.
3. It’s one atom thick, so there’s nowhere for flaws to hide
Most materials fail at defects: tiny cracks, impurities or dislocations. Because graphene is a single atomic layer, a pristine sheet contains almost none of them. It gets very close to the theoretical maximum strength of its bonds.
4. It’s also flexible
Unlike many stiff materials, graphene doesn’t shatter easily. It can be bent and stretched considerably (by more than 20%) before breaking. That combination of strength and flexibility is rare.
The honest caveat: strong sheet ≠ strong block
Those record numbers apply to a perfect, microscopic sheet. You can’t buy a “block” of graphene that is 200 times stronger than steel. Large-scale graphene materials are made of many smaller flakes, and the overall strength depends on how well those flakes bond with each other and with whatever material they sit in.
That’s where composites come in.
How graphene makes 3D printed parts stronger
Adding a small amount of well-dispersed graphene to a plastic such as PLA reinforces it from the inside:
- Load transfer: graphene flakes take on part of the stress that the plastic would otherwise carry alone.
- Crack stopping: when a micro-crack meets a flake, the flake blocks or deflects it, so the crack can’t run straight through the part.
- Better layer bonding: in FDM printing, the weakest direction is usually between layers (the Z-axis). Graphene can help improve strength in that direction.
- Heat management: graphene also conducts heat, helping parts shed heat more evenly.
According to our data sheet, Graphene SuperTough PLA showed the following against standard PLA:
- 25% higher tensile strength
- 35% higher Young’s modulus (stiffness)
- 45% higher strain to failure in the Z-direction, the axis where standard PLA prints usually fail first
- 3x thermal conductivity
It prints on the same settings as standard PLA, with no hardened nozzle required, because graphene isn’t abrasive the way chopped carbon fibre is. See Graphene vs Carbon Fibre Filament for a full comparison.
What to print with it
- Brackets, mounts and clips that take repeated load
- Robotics and automation parts (read more)
- Functional prototypes that need to survive real testing (read more)
- Jigs and fixtures for the workshop
Shop SuperTough PLA 1.75mm or 2.85mm. UK stock, dispatched within 24 working hours.
FAQ
Is graphene stronger than diamond?
Graphene’s in-plane tensile strength is higher than diamond’s, but diamond is much harder (it resists scratching and indentation better). They are strong in different ways.
Is graphene stronger than carbon fibre?
As a single sheet, yes, by a wide margin. In filament form, both are additives in plastic, so the real-world difference comes down to how each is used. Read our graphene vs carbon fibre comparison.
Is graphene filament stronger than normal PLA?
Our SuperTough PLA has 25% higher tensile strength and is 35% stiffer than standard PLA. Full figures are on the data sheet.
