The Ontario SpecPlus line of knives are an outstanding value. The only issue that I have with them is some of their sheaths are a little awkward to use. We have several Spec Plus knives and have come up with an easy way to make a custom kydex sheath that can be modified in a number of different ways.

This sheath will be for our new SP-8 Survival Machete. You can use this method to build a sheath for any of the SpecPlus knives since they all use the same type of Kraton handle.

The materials used for this specific sheath are 2 pieces of .080″ kydex, a 1″ metal D-ring, 7 rivets and 4 eyelets. The sheath consists of a front half and a back half. The kydex should be long enough to cover the blade and three quarters of the handle. I usually cut them longer. It’s better to be too long than not have enough material.

Some thought should go into the back half of the sheath prior to molding it. You may want to cut belt slots into the sheath or fold a belt loop right into the kydex itself. This sheath will either be lashed to a pack or hung from a belt with a keyfob so we’re going to use the D-ring. This is very similar to the arrangement supplied with the factory sheath provided with the SP8. You’ll see in the photo below that we rough-shaped the back prior to heating and shaping it.

Once you’ve decided on a belt slot, loop or whatever, place the back half of the sheath in a 300 degree oven. When it’s fully heated, place it on a 1/2″ board as shown below with the upper portion draped over the edge. Place a heavy board on top of the kydex and let it cool.

The back half of the sheath will look like this. The 1/2″ offset will allow the knife to insert completely into the sheath and keep the handle free from rubbing anything behind it.


Next step:  Place the front half into the oven and place the knife into your kydex press. When the kydex is fully heated, drape it over the knife and handle and close your press.

When it’s cool, remove and inspect it. If you’re not happy with it, reheat it and try it again. (That’s the great thing about kydex!) Your two halves are now ready to be riveted together.

I usually rough shape the sheath as soon as it’s riveted. This is also the time to start working on the retention. In the photo below, circled in yellow, is the spot that I heat and form to the finger guard of the knife. I just use a candle to warm the kydex and form it right to the knife with my thumb. The knife handle should “snap” into place when it is placed into the sheath.


If the rest of the sheath feels too tight, you can use a hair dryer to heat the entire sheath. Work the knife in and out of the sheath until it loosens up.

Now is the time to do the final shaping. Soften all the edges and deburr any fuzz. I use a bench mounted belt sander for the shaping and sanding.

Use a candle to shape the “mouth” of the sheath so the knife can be placed into the sheath without hanging up on anything. A candle was also used to form the kydex around the D-ring and a rivet was used to close the loop.

The eyelets were placed at the bottom and the sides so the sheath could be tied to a pack or a leg if necessary.

There it is. Our version of a custom kydex sheath designed for the Ontario Spec Plus fixed blades.

ALWAYS use eye protection when operating tools and power equipment. Be sure to wear gloves when handling the hot plastic.

Kydex presses are available at




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