by Inside Heinnie Haynes
What is KYDEX?
KYDEX® Thermoplastics is a line of thermoplastic acrylic-polyvinyl chloride materials manufactured by a company called SEKISUI KYDEX who also own the ALLEN® Thermoplastics brand. KYDEX® is a world renowned brand name, with its uses spanning a huge range of industries, for a wide variety of uses. Among them are sheaths and holsters for knives and guns.
The beginning
KYDEX® Thermoplastics was originally the masterpiece of Rohm and Haas Company, a Philadelphia-based materials manufacturer working in the aircraft interior business. It was in the late 1960’s that people started realizing the possibilities that KYDEX® offered. They realized that the sheets could be molded and manipulated into a massive range of shapes, by simply heating and molding around forms. The brand KYDEX® has since changed ownership a few times, but the brand itself has still managed to become almost a household name for molded plastics.
Why is KYDEX so popular for knife sheaths?
There are so many reasons why KYDEX® is so popular.
It has the following advantages:
- Waterproof
- Scratch resistant (Rockwell “R” hardness of 90)
- Holds its shape and will not alter unless forced under
certain conditions - Low maintenance
- Able to simply wipe clean
Usually as the knife is re-inserted into the sheath, you will hear a ‘click’ sound which helps you know your knife is safety secured.
Some companies are going one step further than just using normal KYDEX® Sheaths. These improved sheaths will be designed to be extra quiet with minimal rattle, they will contain rub strips to minimize wear of the knife and its coating and contain weep holes for water drainage among other things.
Are all KYDEX sheaths the same quality?
Much like any other manufacturing materials, there are different grades of thermoplastic.
KYDEX® manufactures over 40 different lines of thermoplastic sheets, each with its own properties and price point, from budget to premium ranges and everything in between.
Be aware though, not every sheath you buy that calls itself KYDEX® is KYDEX®. As you can imagine with any company that produces such a world known product, there are copycats. For example, there are no injection-molded holsters made with genuine KYDEX® Thermoplastics! That’s because KYDEX® is engineered from pure polymers; their extruded sheets don’t contain blended stiffeners (such as glass). KYDEX® lasts longer than cheaper plastic and it’s far less likely to damage your knife, no matter how many times you remove and re-place it in the sheath.
To create a genuine KYDEX® sheath, makers heat a sheet of plastic, mold it around a form, cut off the excess material and polish the finished article. It’s a slower, more labor-intensive process that requires considerable expertise and quality control. For example, the KYDEX® has to be heated to a precise temperature and cooled properly.
Let’s Summarize
A molded KYDEX® sheath is a hand-crafted product. It’s a difference that’s reflected in both performance and the price. You get what you pay for not only in quality of the material, the durability of the product and the considerable time it’s taken to produce, but also in the knowledge that you knife is safe and secure in a sheath that’s designed to protect and serve.
Reprinted with permission from Lorax Ltd.