The ten strongest known materials, ranked by ultimate tensile strength from graphene and diamond to everyday engineering materials.
Quick answer: 1. Graphene, 2. Lonsdaleite, 3. Diamond, 4. Carbon Nanotube, 5. Boron Nitride Nanotube, 6. UHMWPE Fiber, 7. Metallic Glass, 8. Darwin's Bark Spider Silk, 9. Silicon Carbide, 10. Aerogel.
Tensile strength measures how much pulling stress a material can withstand before breaking or failing. It is one of the most important properties in materials science and engineering, determining everything from the cables in a suspension bridge to the fibres in a bulletproof vest. This list ranks the ten strongest known materials by their ultimate tensile strength (UTS), measured in gigapascals (GPa). The top of the list is dominated by carbon allotropes — graphene, diamond, and carbon nanotubes — which owe their extraordinary strength to the covalent bonds of carbon atoms. Nanomaterials and advanced composites occupy the top positions, while more conventional engineering materials such as ceramics and polymers round out the bottom ranks.
Graphene is a single-atom-thick sheet of carbon atoms arranged in a hexagonal lattice. It has a tensile strength of 130 GPa, making it the strongest known material. It is also the thinnest and most conductive material known, with applications in aerospace composites, electronics, and nanotechnology.
Lonsdaleite is a rare hexagonal polymorph of diamond, first identified in meteorite impact craters. Computer simulations suggest it is 58% more resistant to pressure than conventional diamond, with a theoretical tensile strength of 121–130 GPa, comparable to graphene.
Diamond is the hardest naturally occurring substance, with a tensile strength of 90–100 GPa. Its tetrahedral crystal structure of strong covalent bonds gives it exceptional mechanical properties. Diamond is used extensively in industrial cutting, grinding, and drilling tools.
Carbon nanotubes (CNTs) are cylindrical molecules of rolled graphene sheets. They have a tensile strength of up to 63 GPa, about five times that of steel, while being a fraction of the weight. They are used in structural composites, electronics, and nanotechnology.
Boron nitride nanotubes (BNNTs) are structurally similar to carbon nanotubes but offer superior thermal stability and chemical resistance. They have a tensile strength of about 33 GPa and bond more effectively with polymers than CNTs, making them ideal for protective coatings and structural composites.
Ultra-high molecular weight polyethylene (UHMWPE) fibre is 15 times stronger than steel wire of the same weight. With a tensile strength of 30.84 GPa, it is used in ballistic armour, medical sutures, and high-performance ropes. Dyneema and Spectra are the best-known brands.
Metallic glass (amorphous metal) is an alloy with a disordered atomic structure rather than a crystalline one. This structure gives it a tensile strength of about 1.61 GPa, stronger than most conventional steels, along with high elasticity and corrosion resistance.
The silk of Darwin's bark spider (Caerostris darwini) is the toughest biological material known, with a tensile strength of 1.60 GPa. It is about 10 times stronger than Kevlar and can stretch up to 50% of its length before breaking. The spider's webs span rivers up to 25 metres wide.
Silicon carbide (SiC) is a ceramic material with a tensile strength of 0.30 GPa and a Mohs hardness of 9.5, second only to diamond. It is valued for its thermal stability, semiconductor properties, and use in abrasives, cutting tools, and high-temperature electronics.
Aerogel is the world's lowest-density solid, with a tensile strength of just 0.02 GPa, but an extraordinary strength-to-weight ratio. It can withstand compressive forces thousands of times its own mass and withstand temperatures up to 1,200°C, making it valuable for thermal insulation in aerospace applications.
| # | Name | Class | Year discovered | Key property | Common use | Mohs hardness | Brand names | Species |
|---|---|---|---|---|---|---|---|---|
| 1 | Graphene | Carbon allotrope | 2004 | Strongest known material | Composites, electronics | — | — | — |
| 2 | Lonsdaleite | Carbon allotrope | 1967 | 58% stronger than diamond | Industrial cutting, research | — | — | — |
| 3 | Diamond | Carbon allotrope | — | Hardest natural material | Cutting tools, abrasives | 10 | — | — |
| 4 | Carbon Nanotube | Carbon allotrope | 1991 | 5x strength of steel | Composites, nanotechnology | — | — | — |
| 5 | Boron Nitride Nanotube | Non-carbon nanomaterial | 1995 | Thermal + chemical stability | Protective coatings, neutron shielding | — | — | — |
| 6 | UHMWPE Fiber | Polymer fibre | — | 15x stronger than steel wire | Armour, ropes, medical sutures | — | Dyneema, Spectra | — |
| 7 | Metallic Glass | Amorphous metal alloy | 1960 | Stronger than steel | Aerospace, sports equipment | — | — | — |
| 8 | Darwin's Bark Spider Silk | Biological material | — | 10x stronger than Kevlar | Biomimetic materials, sutures | — | — | Caerostris darwini |
| 9 | Silicon Carbide | Ceramic | — | Thermal stability + hardness | Abrasives, semiconductors | 9.5 | — | — |
| 10 | Aerogel | Nanoporous solid | 1931 | World's lowest density solid | Thermal insulation, aerospace | — | — | — |
Materials are ranked by their ultimate tensile strength in gigapascals (GPa), the maximum stress they can withstand while being stretched or pulled before they fail. Values are drawn from peer-reviewed materials science literature and authoritative databases including NIST and ASM International. Where a material's strength is reported as a range (e.g., diamond at 90–100 GPa), the upper bound of the generally accepted range is used for ranking. The list covers all known classes of materials — natural and synthetic, organic and inorganic — but excludes materials that are not yet experimentally verified beyond laboratory conditions. Only bulk material properties are considered; single-atom or quantum-scale phenomena are noted where relevant.
Tensile strength measures resistance to being pulled apart, while hardness measures resistance to surface scratching or indentation. Diamond is both extremely hard (Mohs 10) and has high tensile strength (100 GPa), but graphene has higher tensile strength despite being a single-atom layer.
Graphene is being commercialised in applications including conductive inks, composite materials, battery electrodes, and thermal management films. However, producing large-scale, defect-free graphene remains challenging, and many consumer products claiming to contain graphene use graphene flakes or derivatives like graphene oxide.
The top materials — graphene, diamond, carbon nanotubes — are carbon allotropes held together by some of the strongest chemical bonds known. The jump from #6 (30.84 GPa) to #7 (1.61 GPa) reflects the difference between nanoscale carbon materials and bulk engineering materials, where imperfections and larger atomic structures reduce overall strength.