What is Kydex? (And Is It Good For Knife Sheaths?)

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Kydex is basically a thermoplastic that is made from acrylic-polyvinyl chloride that was originally designed in the mid-’60s to be used in the interior of aircraft.

Since then, this revolutionary material has experienced widespread use in different industries and products that include the automotive industry, making safety helmets, trays, insulators, telescope bodies, and most importantly knife sheaths.

Kydex was originally developed by Rohm and Haas in 1965 and since then, it has continued to be loved primarily because of the acrylic-polyvinyl chloride compound.

This compound allows Kydex to have the rigidity of plastic and, also being a thermoplastic, it allows it to be moulded to different shapes.

Properties such as formability and rigidity, found in acrylic and other properties such as chemical resistance and durability found in polyvinyl chloride, make Kydex ideal for thermoforming fabrications.

What is the thinnest Kydex for a knife?

Kydex sheets for knives are available in different sizes with the common ones being .060, .080, and .093 for the thin variants.

The thinnest Kydex sheet you can get in the market is the .060 size.

The greatest benefit that comes with using the thinnest Kydex sheet is that it is the most flexible, and at the same time will offer the greatest definition for your sheath.

Thicker Kydex sheets might hold your knife in place better but might not offer as much definition on your sheath as the thin ones.

Are Kydex holsters good for knives?

Not only do Kydex holsters offer more retention to the holster to hold the knife in place when compared to other materials, but they are also more durable and offer more strength.

This makes them ideal to be used for knives.

To put this into perspective, Kydex registers a hardness of 90 on the Rockwell scale while a gun barrel registers between 26 and 40 on the same scale.

On top of this, the Kydex holsters are lightweight and very durable. Due to their moulding ability, they can be vacuum-formed to make holsters with a thin profile and create that perfect fit for your knife.

What are Kydex knife sheathes?

There are a bunch of benefits of using Kydex for knife sheaths and why they are very popular.

First and foremost, Kydex is a waterproof material that repels off water hence it doesn’t lose its shape unlike other sheathes.

Secondly, Kydex is very scratch resistant with a rating of 90 on the Rockwell scale which means you don’t have to worry about your knife causing damage.

This leaves your sheath looking newer for longer.

Additionally, this type of knife sheaths do not deform easily and hold their shape unless pressure is applied under certain conditions that include heat.

Moreover, these sheaths are extremely low maintenance as you can easily wipe them clean quickly.

Finally, Kydex sheaths offer some sort of security when you reinsert your knife into it by hearing a clicking sound assuring you that the knife is safe.

There are some organisations that are continually seeking to improve the traditional Kydex sheaths.

They seek to better these sheathes by trying to create ones with the least rattle so that they are extra quiet. They are also trying to include rub strips on the inside that will reduce wear on the knife and also it’s coating.

Finally, they are also to include weep holes on the sheaths to allow water waste to exit easily keeping the sheath clean and free from water.


Kydex knife sheaths do a better job in holding your knife securely in place, are durable, and are significantly lighter which makes them almost a necessity on your next hunting adventure.