The Cutting Edge

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15 Cool Knives with Unique Opening Mechanisms

One of the things I love most about the knife community is the constant quest for innovation and freshness. While I love dissecting the minute changes in the latest flipper, it’s those completely ground-breaking models that keep me in awe.

For a tool that’s been around for a couple million years, the knife is still experiencing some pretty radical changes and creativity. While these knives can be hit-or-miss and many have been discontinued, they stand as evidence that no matter how long something exists, great minds can always think outside the box.

Here are 15 knives with the most interesting deployment mechanisms.

1. Kershaw ET

Kershaw ET

Let’s start off with one that most people will instantly point to when you mention unique opening mechanisms:  the Kershaw ET. Standing for External Toggle, the ET hails from the genius minds of Grant and Gavin Hawk. This father and son duo has developed some pretty out there designs like the TOAD, Boker Griploc, and many more.

The Kershaw ET uses a toggle mechanism to open and close the blade. You can actually engage the blade through many ways (using your thumb like a traditional folder and dropping the handle while holding the blade), but the toggle is probably the most fun. You can use a lever near the butt of the handle to open and close it. The knife was discontinued, probably because there’s the danger of the knife closing on your thumb when you use the toggle.

Here’s a gif of how it opens with the toggle from this review:

kershaw et gif

2. CRKT Rollock

CRKT Rollock

Next up is another discontinued knife. The CRKT Rollock is a fascinating knife with a cool opening mechanism. To deploy the blade, you press down on the blade (specifically on some jimping near the rear of the spine) when closed. That pops the blade up, and then you slide it completely open.

This factory version from CRKT was inspired by the Rolox from Blackie Collins. Collins is often cited as the first person to create an assisted-opening knife, though Ken Onion may have invented the SpeedSafe assisted opener concurrently.

Here’s a gif from an old YouTube :

3. Paragon Knives by Asheville Steel Warlock


The Warlock from Paragon Knives by Asheville Steel (I know that’s a mouthful) is actually a new knife. Not quite an automatic knife and not quite an assisted opener, the Warlock is its own category. When shut, the blade is completely invisible. So how do you open this baby up?

With the press of a button, the handle opens up (think Moses parting the sea) and you use gravity to take it home. The same thing goes for closing it. When the handle parts, the blade slides back inside. You’ll want to make sure the knife is held the right way or your palm could be in for a rude surprise.

Check out this gif of the Warlock in action:

4. Scorpiodesign Shapeshifter EDC


Prepare to have your mind blown. The Scorpiodesign Shapeshifter may have one of the most unique opening systems. When closed, the knife hardly even looks like a knife. If you’ve never used one, it’d take a few moments to figure out how to use it.

Basically, as the tip of the knife travels through the butt of the handle at an angle, the middle portions folds into itself and snaps into place. I’m not doing it justice in my description. The knife is meant to be a great EDC knife, but it seems like it would take a lot of time getting used to it.

5. CRKT Fulcrum 2

The Fulcrum from CRKT was discontinued, but it made a comeback with the Fulcrum 2 in 2016. This Russ Kommer design uses a patented opening mechanism called the Fulcrum Action. So how does it work? When the left side of the frame is pressed with the thumb, the blade swings open about 90 degrees. When the left side of the frame is pulled back, the blade opens the rest of the way. The cool part is that when you’re opening it, you can see part of the inside of the knife.

This new version of the Fulcrum has a 2.75-inch blade and swirled CPL handle scales. It’s a great knife to play around with when you’re bored.

This is the original Fulcrum from a CRKT video:

6. Schrade Viper Side Assist


Most people are familiar with the out-the-front knives, but how about out-the-side? The Schrade Viper Side Assisted Opener deploys the knife from the side of the handle. When closed, one side of the handle shows the blade waiting inside; the other has a peculiar hole toward the top. To open up the knife, you simply push the blade through the hole until the spring assist activates and sends the blade hurling open.

To release the 2.5-inch blade after it’s open, you pull back a button on the handle and then push it closed. A safety button keeps the knife from engaging when you don’t want it to.

Here’s the knife in action from Schrade:

7. A.G. Russell Funny Folder


The Funny Folder from A.G. Russell is an aptly named knife. The design is actually fairly old, more than 50 years old to be exact. To deploy the blade, you push the handle from the side while holding the frame (not unlike the Schrade Side Assist). Once the handle is fully opened, you pivot part of it back to reveal the blade.

It has a drop-point blade and a titanium handle. It’s not a hard use knife, but it is fun to use. Funny folder indeed.

This is the Funny Folder in action:

8. Lone Wolf Defender


The Lone Wolf Defender was the 2009 winner of the Overall Knife of the Year award at Blade Show. The designer of the knife, Paul Poehlmann, invented the Paul Axiel locking mechanism, which can be seen on the Defender and a few others.

One way to open this knife is to hold the pivot between your thumb and index finger with the handle pointing upward. When the pivot is depressed with your fingers, the blade unlocks and the weight of the handle will cause it to fall, revealing the blade. To close it, you do the same thing but in reverse.

This is another fun way to open and close your knife. The Defender is billed as a tactical gentleman’s folder with a 3.9-inch blade made from 154CM steel.

Check it out:

9. CRKT Snap Lock

Yet another winner of the Overall Knife of the Year award at Blade Show — this time in 2004 —the CRKT Snap Lock is a design from the creative mind of Van Hoy. This is another in a line of folders that open from the side. To engage it, you use your thumb to depress the thumb wheel and open up the blade. There is a thumb wheel on each side for ambidextrous opening.

The big advantage of the Snap Lock is that it opens from the side, meaning when you’re applying pressure to the blade, it is less likely to fail.

The CRKT Snap Lock was discontinued but made a comeback.

Here’s a gif from this short video:

10. Smith & Wesson Power Glide


The Smith & Wesson Power Glide could be considered an OTF knife, but it’s not like the others. The blade does come out the front of the knife, but the fun part is getting there. When you pull the closed handle apart, it’ll reveal two aluminum crosspieces that connect to the bottom of the blade.

The farther you pull the handle apart, the more the blade comes out of the top. Once it gets halfway, you’ll have to give it a little nudge and then when it closes, the blade comes out the rest of the way. Then the handle locks up at the bottom.

This is a cool knife that’s not entirely practical for hard use, which is probably why it was discontinued. Still, it earns marks from us for its cool opening mechanism.

11. Pacific Cutlery 983 Barry Wood


Back before there was Benchmade, the iconic company was known as Pacific Cutlery (and Balisong USA before that). The balisong has a unique opening method, but since it’s a pretty common opening style, we won’t include it here. But the cool opening design from Barry Wood fit right into the balisong-focused line of Pacific Cutlery.

The Pacific Cutlery 983 Barry Wood is pretty close to a balisong because Barry Wood’s interesting swing lock pivots the handles open to reveal the blade. You essentially rotate one of the handles all the way around. In the process, the blade locks open.

Barry Wood’s swing lock is actually featured on a number of his custom knives. Even though he passed away in 2014, his son-in-law Mike Irie still makes some knives with the swing lock.

I couldn’t find a better video than this, so you’ll have to see this gif with a partial view:

12. Fox Knives aX Dobolock


In 2011, the winner of the Imported Innovative Knife of the Year award went to a little knife called the aX-Dobolock. The Dobolock is an ingenious design that’s similar to Paragon Knives by Asheville Steel Warlock and the Schrade Viper Side Assist. To open this bad boy up, you press the top of the handle to make it open up from the bottom. Once one side of the handle is completely open, you whip your wrist to get the blade back up to the top. Then you snap the handle shut again in a swift motion.

Writing it out makes it sound clunky, but you it can be one quick cohesive motion with a little practice. You use a hole in the side of the handle to push the other handle open in order to close the knife, if that makes any sense.

Here’s a gif slowing down the action because you can’t see it when you do it at full speed:

13. CRKT Daktyl

The fact that CRKT has a fourth knife on this list of 15 means the company is really into producing some innovative designs. The Daktyl is actually a reimagining of the original Hole in One design Tom Hitchcock made with CRKT.

The Daktyl has an open design with no enclosed handle. The knife is pretty similar to the CRKT Snap Lock by Van Hoy. It opens from the side.

This review shows the Hole in One in action:

14. Camillus Dominator


The first thing people try to do when they see the Camillus Dominator is figure out whether it’s a fixed blade or a folder. The blade is fixed, but a folding mechanism reveals the blade.

When the knife is closed, a protective mechanism covers the blade, making it safe and easy to carry. To open it, you press down on a notch and pull the cover mechanism back to reveal the edge of the blade. This is unlike most of the others on this list, but it’s an interesting design that I hadn’t seen before.

15. Fred Perrin Le Tri-Folder


Finally we have the Fred Perrin Le Tri-Folder. When you get it down right, you could whip this knife around so fast that it looks exactly like a balisong in a skilled person’s hands. The knife is three pieces of metal each connected to only one other piece by a pivot screw. When you open it up, the blade swings out and you close the handle again to make a virtual fixed blade.

Then you open it up and swing the blade back inside. This is similar to the Cold Steel Triple Action Folder that came out some time later (and has been subsequently discontinued). It does take some getting used to, but once you do, you could have the knife open and ready to go in an intimidating second.

Here’s a slowed down version of the opening mechanism, but like I said, it can be as fast as a balisong:

Want to See More Weird or Unique Knives?

Check out our archive of posts with weird knives or take a look at some of our other favorite posts, including 10 Insane Art Knives, the Most Bizarre Spyderco Designs, and the Knives with the Strangest Blade Shapes.


  1. I believe I have a “funny folder” like the one above but it’s marked as a Smith & Wesson. Probably from the 90’s.

    • Yup, have one too.
      Got to be pretty fast deploying it like a butterfly. Poor quality steel, but easy to conceal due to the flatness of the knife.

      • @Sean, I’ve got one of those S&W blades too. The steel is so poor that when I accidentally dropped it from maybe 2.5 ft & it snapped into TWO(2) pieces! When I attempted to return it to the manufacturer they refused to replace it or even refund my money! Terrible steel & horrid customer service. I guess that’s what happens when we outsource to other countries.

    • I have a butterfly knife get on my level

  2. are any of these knives avable for purhase?

  3. are any of these knives avable for purhase

  4. Love the Lone Wold Defender. Great knife

  5. Outstanding look at some innovative designs, the good and the bad!

  6. The funny folder was named and brought back into the public eye some 40 years ago by the late T.M. Dowell. Dowell evolved the knife a bit and usually carried one when he hunted. Dowell is known for inventing the modern integral hilt and integral hilt and cap, possibly the strongest way to make a knife. He was one of the founders of the Knifemakers Guild and served a term as president in it’s early years. Dowell fought for the guild to produce their own show. He made mostly hunting knives but the handful of art knives he made were brilliant

  7. ScorpioDesign Shapeshift EDC much for two samples or it is bargain to order two items?Thank u


  8. They all suck. You shouldn’t need to use both hands to open a knife and it shouldn’t take 2 or 3 or more steps to open a knife. My current EDC is a Kershaw Leek. Small, light, sturdy, sharp as hell and opens in a blink, in one hand, with a single movement, and in position ready to go. Some of these may look pretty good – the Warlock, the Fulcrum, the Lone Wolf and Power Glide in particular, but they are more just curiosities than anything practical.

    • These aren’t tactical knives. They are curiosities with an edge. The mechanism is the thing, not the speed of deployment. They are fun and interesting first; and edged tool second.

      Harry Truman say that there are as many ways to do a thing as there are men who want to do it. Lighten up, take time to enjoy life. You’ll be glad you did.

  9. It took a while to master opening and closing the CRKT Snap Lock ! Sweet knife, it’s a shame it is discontinued. Went to buy some so family and friend could have one and it was gone.

  10. I love my crkt ful crum2
    It is a great knive !

  11. Darren Davenport

    October 25, 2016 at 10:50 am

    I think Marbles did the tri-folder before or at least they did make one sadly another no longer able to buy in the uk i think uk customs would call a few of these illegal which sucks as they all are so cool i love the quirky openers and would love to buy the lot great artitical really enjoyed this one great job guys .

  12. Schrade Viper Side Assist is coolest of them all! 😀

  13. Wow¡¡ Awesome and very nice penknives. I’d like to have all them in mycollection

  14. Neil Ashby II

    May 31, 2017 at 12:49 pm

    Re: Fred Perrin Le Tri-Folder.

    Well made but like with Case (361) and Cold Steel then this design has been wrongly referenced as “Tri-Fold”; it folds twice and is therefore the Bi-Fold design.

    • The tri part could refer to the knife being made of 3 pieces, the fold part , well that’s pretty self explanatory lol

  15. This (That) (These and Those…. lol) is true. You should take time to enjoy life and you will be glad you did.
    Another thing that is true is that if a knife can be interesting in any way, such as looks or opening mechanism examples are butterfly switch utility conceled spring assisted knives.
    And something that I notice is that all of these have very quality examples. And from what I am hearing about these knives above is that they are poor quality in ways such as poor metal and this can be fixed. So why does not somebody do this. This is the most interesting point about these low quality knives and if you understand than you can enjoy this and therefore enjoy life as well.

  16. thanks for conversing.

  17. Hi Tim,
    Thanks for the superb article. I love it for three main reasons, also I want to share some good news for all of your readers.
    First, I’m fascinated by mechanisms, knives and locks.
    Second, The gifs are so information dense, I doubt you could find better weird knife lock porn anywhere.
    Third, you have chosen two of my designs, the Snap-Lock, which I designed with Ed VanHoy, and the Hole in One. Sadly both were discontinued due to the sudden closure of the manufacturer.
    The good news, CRKT has re released the Snaplock and introduced a smaller version of the Hole in One, called the DAKTYL, with a new locking feature. Check it out.

  18. Thanks for this nice blog, It really help to know about Knives.

  19. JaySteel Blades

    June 14, 2018 at 2:39 pm

    I own a Funny Folder. And It DOESN’T Require 2 hands!! NOR is it awkward to open!! I just flip it down and backwards in one motion. Takes less than a second!! (from Closed to Open blade) If you are not getting it U R doing it wrong!! I Will show U step by step pics how to really do it, just email me [email protected]

  20. The Camillus Dominator reminds me of Marble’s Safety Axe design.

  21. One word comes to mind (actually two words); Rube Goldberg! What advantage is there to any of these over the operation of a knife with a thumb-stud or thumb hole ala Spyderco?
    Amusing to look at but I wouldn’t give a nickel for any of them.

  22. You left out the Spyderco Meercat… Well, it opens normally; it’s the closing that’s the trick.

    I used to have a CRKT Rollock. It got lost, or maybe it’s somewhere in storage.

  23. Very cool knives

  24. Thanks so much for sharing! By the way, I have a question that “How to open a tactical knife?”. Can you help me?

  25. One of the best articles but most of your knives are unavailable, by following your articles, I choose the Camillus Dominator knife but it’s unavailable, if you know any store that can sell these types of knives then kindly let me know. I love this design.

  26. I received a “funny folder” in Hungary 52 years ago, when my family visited my great uncle. Sadly, when I got back home I showed it to all my friends (and others), and poof it disappeared one day. Very cool piece for a 12 year old.

  27. Thank you for all the information. Best knife site ever. I am trying to identify 50 years of knife collecting and you are the go to guy.

  28. Wayne Zieschang

    October 28, 2022 at 7:30 pm

    The Tri-fold was made by Kabar and Marbles (and maybe a couple of other companies) back before WW2 to much greater quality standards that this “modern” take.

  29. Thanks much for sharing!

  30. Lone Wolf Defender on eBay is $1200, and it’s not even the decent looking one shown on here. They forgot the old-school gravity knife which, although small, was still one of my favs.
    I am still looking for/trying to find the old kind of knives that pushed-out the front with your finger/thumb. Mine was camo, but I know they made them in black and other colors. The blade was spring-loaded in reverse. So you would use your thumb to push it from the back forwards to the front and push it slightly down so that it locked into place with the bade out-the-front. It was NOT an automatic though. I guess you would call it a “glide” knife. You glided it up and out via your thumb. Then you just pushed the unlock button or whatever, and the blade would retract back inside the handle quickly. I have no idea who made them or what they were called though. Anyone know?
    Please advise.
    [email protected]

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