Why Should You Have a Kydex Sheath

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Just using a knife efficiently is a job half done. This is because it is equally important to take care of it so that it stays protected and, consequently, functional for a longer period than what you may have expected. Ensuring proper protection is critical for retaining a knife’s edge and looks.

This is the reason why most knife users will always recommend investing in a good-quality knife sheath. Apart from the required protection, a sheath is essential for carrying your knife no matter whether you go on an adventurous tour or go out in your backyard for preparing for a BBQ party.

While there are knives that come with their tailored handmade sheath, many do not. If you have one such knife, it becomes essential to buy a sheath separately. Different types of sheaths for knives are available, each varying in size, thickness, appearance, and build material.

While leather is a popular build material, the Kydex material is getting more popular these days. Yes, knife users are looking for Kydex knife sheaths despite leather being an ideal and favorite option for many.

Let’s face it; leather looks classy. It even functions well. However, for reliable daily use, it has its limit. Further, the rising awareness of animal cruelty makes several of us look for alternative and better build materials.

As polymer variations find their way into the hearts and markets that were otherwise reserved for the older wood, steel, and leather builds, the biases against synthetics have significantly vanished. If your daily-use knife profile requires optimal and maximum performance, you are bound to find your way to a Kydex sheath maker.

So, let’s find out more about these sheaths.

SOG knife with Kydex Sheath

Evolution of Kydex

The Kydex material has been in use since the 1960s and was initially made for application in the airplane interiors. Since then, the material has proved versatile enough to adapt to a myriad of other items and industries, ranging right from helmets to telescopes and from auto parts to trays.

For the firearm and tools industries, the material is useful for making knife sheaths and holsters. It was initially tried as a holster material by Bill Rogers in 1972, who was a young, creative FBI agent.

Bill was fed up due to how the leather holster stretched, sagged, and finally deformed after use. This pushed him to come up with his new material. This material was Kydex!

His work on this material resulted in a high demand for the material so quickly that he took leave of three years from the Chicago Bureau for producing holsters. It took 20 more years for synthetic options to become an ideal alternative to conventional leather.

During that time, molded Kydex and injection molding evolved as two alternate methods for making firm synthetic holsters.

So, What Is Kydex?

Made by Hass and Rohm in 1965, Kydex is derived from plastic. It chiefly is a thermoplastic blend of acrylic and polyvinyl chloride components. It ensures plastic rigidity while contrastingly enabling it to be molded into different shapes.

Obtained for thermoforming fabrication, Kydex has the properties of both polyvinyl chloride and acrylic. The former ensures chemical resistance and durability, while the latter renders rigidity and formability.

Kydex is a hard thermoplastic, as it has a hardness level of 90 on the Rockwell scale. This is astonishingly more than the hard gun barrels whose hardness level on this scale is around 26 to 40. This high level of hardness, along with the typical grained surface, ensures a higher resistance to abrasion than usual.

In a nutshell, Kydex is light and durable polymer that forms easily upon heating. It is possible to apply the vacuum forming procedure to it for ensuring an ideal fit.

The material is also capable of yielding a slimmer shape than its injection-molded equivalents. Moreover, Kydex sheaths are durable, strong, and retain themselves better than their injection-molded equivalents.

The injection-molded alternatives were utilized in different versions since the 1800s. The procedure of injection molding uses a mix of molten ingredients, usually nylon polymers, to insert it into a mold. This results in the production of the volume, consistent output, and reduced manufacturing overheads.

However, the compromise is the overall quality. In other words, an injection-molded sheath may wear out swifter than a Kydex equivalent. Further, it is less likely to inhibit the exact fit of a costlier alternative.

Regardless of the disparities in manufacturing methods, the end product usually functions the same. Both sufficiently retain the outcome well, although that made from Kydex fits into different variations a bit better.

Further, both tend to maintain their shape for long, are waterproof, and are capable of getting rid of sweat and dirt.

Is Kydex Likely to Break?

Without any doubts, no! Nevertheless, if you abuse it too much, it is likely to lose its shape or break. If hassled relentlessly, it may take no time for the material to show cracks at the spots of stress.

You should avoid leaving your Kydex sheath, where it is hot. It is likely to distort at high temperatures.

In case your Kydex sheath has hardware such as screws, ensure to apply Loctite to clasps for enjoying the benefit of positive retention. Good makers usually rely upon .08-inch Kydex material, as it provides the right balance amongst being lightweight, durability, and full-day usage comfort.

Benefits of Kydex Knife Sheaths

The powerful features of Kydex make it a popular knife sheath material. So, let’s explore them!

First, as the material is composed of thermoplastic, it is not susceptible to harm from moisture or liquids such as water, oils, and acids. This means that you need not worry at all if you accidentally drop your Kydex sheath in a pool of water while cleaning.

What is more is that if the sheath becomes dirty, it is easy to clean and maintain due to supportive Kydex material. These sheaths are also among the most durable sheaths present in the sale.

They do not break even if you drop them on hard ground. Further, they retain their shape over time; there is no place for warping, expanding, or shrinking from any corner.

The material of Kydex has more useful properties such as waterproof, low flammability, resistance to scratches, excellent shape retention, low friction level, ease of cleaning, and resistance to stretching or shrinking in typical situations.

All these qualities together make Kydex sheaths more durable than other materials, without triggering any signs of wear and tear. As these sheaths will last for years, they are worthy of your money.

Benefits of Kydex Over Leather

Leather sheaths are nice and last for a long time. While having a generous character, these sheaths tend to suffer from reasonable downsides. They need more maintenance than Kydex to make them retain their proper shape. They also cost more than the Kydex counterparts.

Leather sheaths retain moisture and sweat, soak oil, distort once the knife is removed, and expand and sag with age. On the other hand, Kydex has none of these shortcomings.

It comes with a lower friction coefficient. In simple words, this translates to a quicker draw time, which is useful for gun users. Kydex features a smooth inner surface that is not as abrasive as leather or hard plastic. Thus, its sheaths shall conserve the finish better than any other sheath build material.

Further, while a leather sheath is preferable for a fixed-blade knife, it is neither durable nor waterproof as a few current time options. Kydex is one of these options.

It is a low-maintenance and durable material for carrying your beloved blade. Plastic or polymer sheaths are capable of taking more abuse than their leather equivalents.

You also have the option of hybrid holsters that feature a mix of Kydex and leather. They, too, are good options. However, a simple Kydex sheath seems to be the most reliable as well as a comfortable choice for everyday carry. It is also easy to clean this material.

Here is a comparison by WBK knives on youtube.

Limitations of Kydex Knife Sheaths

Despite all its excellent pros, Kydex, just like any other build material, has its limitations. The most significant limitation that Kydex sheaths suffer from is its ability to dull the blade stored inside.

Frequently pulling and pushing your knife inside this thermoplastic sheath makes the edge feeble enough to leave its sharpness, and you will have to invest in a good sharpener.

Well, a relieving fact here is that this drawback only applies to a knife that does not fit nicely in the sheath. This means you frequently end up forcing your blade to come in and out of it. Thus, this limitation is certainly not a genuine one.

Another limitation, as revealed by a few knife enthusiasts, is that a Kydex knife sheath is not visually appealing due to its minimalistic design. Mostly, these enthusiasts are those who still are inclined towards the classy leather look.

While the simple look of Kydex sheaths is a fact, it is not an issue with those who do not care about the looks and are more inclined towards a functional sheath. No, this does not mean that those who look for aesthetics are not bothered about functionality.

It is just to say that appearance is not a top priority for many, but functionality is.

Styles of Kydex Sheaths

At the time of buying Kydex sheaths, you will come across the following two styles:

  • Taco: A single Kydex piece is doubled over like a taco for making a sheath. A few buyers prefer this type of sheath for knives to be hung around the neck. This is perhaps because it is somewhat more compact than the pancake style. Further, it is not that heavy or large.
  • Pancake: Two pieces of Kydex are used, of which one goes on the front and the other on the rear for making a sheath. It is easier to make this style of the sheath. Thus, it is the ideal style to consider for making a sheath for the first time.

Ways to Make Knife Sheaths Using Kydex

There are two methods of making a sheath with the Kydex material. Both of them employ a heat treatment, followed by pressing the material with a molded gun to give its shape around the mold.

The other method involved the application of vacuum forming in which a vacuum drags the plastic over a mold. This dragging happens until it becomes cool as well as rigid once again. You can utilize a mold tool or a real object for making a knife sheath.

Overall, it needs skill, know-how, and experience to make the right form to the Kydex and make it usable once molded. However, the equipment required to make sheaths is not very expensive. Thus, you need not worry about the financial aspect of making your Kydex sheath for your knife.

Making Your Own Kydex Sheath

If you are a kind of a DIY person, you will love to make a Kydex sheath instead of buying it. The good news for you is that it is easier to make an excellent looking Kydex sheath than you believe. So, let’s get started with the materials and tools required for the same.

Items Required

Collecting all the needed tools and materials is perhaps the first step to sheath making. Below is the list of the same:

  • Kydex sheets that are readily available at any hardware store or specialty shop whether on-street or online; the most affordable ones are usually available online
  • An oven for giving heat treatment to your sheath
  • A press or a vice clamp to provide the desired shape or form to your sheath
  • A saw or a knife to remove excess Kydex portions
  • Sandpaper for smoothening the end product
  • Eyelets for securing the sheath’s structure; they are available online at discounted prices
  • Gloves for the safety of your hands
  • Ruler for measurement
  • Drill and drill bit and hand setter kit/hammer for drilling holes for inserting eyelets

Typically, Kydex sheets are available in a couple of sizes, of which the most common ones are .06, .08, and .09. It is recommended using the thinnest sheet, as it is the most flexible option to form the best shape for your sheath.

On the other hand, the thickest one is known to hold the best. However, it will not be flexible enough to give the desired sheath outline. If you are confused, it is fine to use a sheet of medium thickness. As per the kind of sheath you are making, you will have sufficient Kydex material to design more than one piece of the sheath.

With these materials and tools, it is time to start with the Kydex sheath making the process. Below are the detailed steps for you to follow:

  1. Identify the right size for the Kydex sheet you require for your knife by laying it out on a table. Consider adding some more size to be on the safer side. This is because it is easier to cut the surplus part than to add one if you end up making it too small. In this process, you just cannot add extra. Finally, cut the sheet to gain the desired size, such as a square size of 9 x 9.
  2. You start with the heating procedure. It is very critical to heat the sheets at the time of designing them. This is because it is the heat that makes these sheets quite supple, which is essential for ensuring a perfect fit that any quality sheath will possess. To get started, perform the following sub-steps:
    • Preheat your oven to 275 degrees Fahrenheit. While the oven is preheating, just keep your press and other things ready.
    • Once heated, place a sheet inside in an aluminum foil or on an oven-friendly pan.
    • Allow it to heat for some minutes. The exact duration is dependent on the chosen sheet size and the oven.
    • Monitor the heating process. When ready, the sheet will be soft and supple to give a rubbery feel. It should not be too hot to start melting. Still, you need to be careful, as the sheet is going to be very hot!
  3. Now, it is time to mold the sheath (right now in the sheet form). Once the sheet gives you a pliable feel and is out of the oven, perform the following sub-steps:
    • Wear your gloves before you touch the sheet. This is because the Kydex is super-hot at this time.
    • Put the knife’s blade over the sheet in your desired position and fold the latter atop the blade.
    • Stick the sheet into the blade by pressing it for a couple of minutes.
    • Take off the clamp once the sheet cools down completely. If you are okay with the way the sheet has molded around your knife, you have completed the step. However, if something is not as per the requirement or has got crooked, consider repeating steps 2 and 3. If you do not want to re-heat, a good alternative is to use a heat gun for making small adjustments.
  4. Now, you can design the sheath. However, before doing so, it is wise to leave enough space for installing the eyelets for fastening the sheath. It is fine to lay the eyelets on the sheet to know the exact space they will take so that you can reserve it for them. You should use a fine point permanent marker to draw your design and highlight the spots where these eyelets will fit. The holes must be of the eyelets’ size, for which you will have to take all markings and measurements before drilling. Now, perform the following sub-steps for drilling the holes before cutting the surplus Kydex and pressing the eyelets:
    • Remove the knife so that you do not accidentally drill into it.
    • Use a drill press along with the hand setter kit or a regular drill to make holes and obtain an even press on the eyelets. In the absence of a press, consider using a hammer and tap them evenly to keep the risk of splitting at bay.
    • Add your eyelets to the holes.
  5. This is the actual step of designing the sheath. You now cut the sheet such that you end up with a suitable sheath structure. As a rule, leaving a gap of 1 cm along the blade’s tip as well as the edges is sufficient to have a snug fit. The more you cut, the less sanding you will have to do. You finally get the rough shape, which now you will have to fine-tune and make all edges appear nice.
  6. This is the step dedicated to sanding to even out everything. By sanding the sheath’s edges as well as the surface, you make it look visually appealing. The edges tend to look smoother just as it is professionally crafted. Another plus point of sanding is that your Kydex sheath looks more ready for painting, which is good news for those who wish to do so.
    That’s it! Your Kydex sheath is ready! If you wish, you can customize it further, etching an artwork. Doing so will make your Kydex sheath look elegant.

Alternatively, refer to this great guide by Walter Sorrels on Youtube


A Kydex knife sheath is tough, resistant to scratching, waterproof, highly durable, need less maintenance, and holds its shape better without shrinking or stretching. It is capable of enduring more abuse than a leather counterpart.
Even though the look can be plain, it is worth considering this sheath. If you are looking for such a sheath for your knife, you can choose to either buy it or make your own.