What is the Sharpest Knife in the World – Obsidian Blade

The sharpest knife in the world is an obsidian knife. Even though it is inappropriate for use in the kitchen,  the fineness of an obsidian blade makes its sharpness unique. In this article, we will explain the world ‘s sharpest knives and their impact as well. We will also describe why obsidian knives are very sharp and why it is highly recommended to use it in your kitchen.

What Affects the Sharpness of the Knife?

The most important factor affecting the sharpness of a blade is its thickness or density. The thinner the blade, the less force required to cut food or anything for that matter. A good analogy to use is to dive into a pool of water. If you jump into the water, you’ll have a really hard time hitting the surface. If you dive into the pool finger-first, however, the thin, pointed shape created by your body will slide easily into the water. The same method is applicable for the edges of the knife.

The Sharpest Knife in the World

Currently, Obsidian Letter Opener knives are the sharpest knives in the world for everyone. Its extremely thin blade is the reason for its popularity. As the obsidian knife breaks it’s called a conchoidal fracture. Its fracture will be very different from the edges of an ordinary chef’s knife. When you zoom in to the steel blade you will see more saw-like edges rather than straight lines. With a conchoidal cracking, the line is straight and therefore sharp.

How Sharp are Obsidian Knives

The obsidian knife’ blade has a 3 nanometers across edge which is ten times sharper than the sharpest razor blade. From that thing, you can estimate how obsidian blades are highly sharpened. 

How Strong is An Obsidian Blade?

The obsidian blade has high strength but can break as well. Its hardness ranges from 5 to 5.5 on the hardness scale. Diamonds come in around a 10 on this scale, so obsidian is middle of the road here. But the downside is that it can crack and break because it is made of brittle materials.

Why Don’t we Use Obsidian Knives in the Kitchen

As we say it is easy to break and it can also leave glass shards on the object we are cutting. Obsidian has been tested as a potential material for surgery but unfortunately it is often quickly discarded. Because when it breaks down in use, it releases material and that material will not be good for humans. The same logic would hold true for food.

What are the Obsidian Knives Used For ?

Obsidian knives having black Obsidian Decor are not widely used these days, but they were used as power tools in the Stone Age. Recently, these knives are also used in medical contexts. The precarious, brittle nature of obsidian means that it is much less common as a cutting material today.

What About Commercial Kitchen Knives?

There are variety of products are available which claims to be highest sharpest but we should need to focus on these aspects: 

  • Thickness of blade
  • Single and double edges sharpening style
  • Reviews for a specific knife

With routinely sharpening and good maintenance you should not worry about and can get the sharpest knife in the world.

Read more: https://knifeplatoon.com/how-to-keep-kitchen-knives-from-rusting/

Frequently Ask Questions

Are Obsidian Knives Sharper Than Razors ?

The edges of an obsidian knife are 30 picometres while the razor blade is 300 to 600 picometer which means that an obsidian knife is 10 times sharper than a razor blade.

Which Knife’s Steel Gets the Sharpest ?

Carbon steel knives are sharper and harder than other knives, it also has high durability and keeps itself sharpened for a long time.

What is the Sharpest Knife in the World ?

For sure, the obsidian knife is the sharpest knife because of their thin edges. But if you are looking for a knife for your kitchen then it will not be safe for you.

Why Don’t we Use Obsidian Knives in the Kitchen ?

Obsidian knives are very fragile and if you use it in your kitchen to work with your food then it may break and particles will spread on your food that are very harmful to you. Due to this reason, we don’t recommend using it in your kitchen.


Now all of us know what is the sharpest knife or blade in the world. Yes, the answer is obsidian with some limitations of use. This knife is not suitable for use in the kitchen because of theri brittle characteristics. Make sure that while using this thinner knife you are really careful with the sharpness otherwise you can cut your hand.

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