The Locking Knife Sheath History

Years ago, some of my military clients (USAF Pararescue, our nation's top military rescue service) asked me if I could make a true combat grade locking sheath, one that would hold up to the rigors of real combat, something that they could trust to have their knife ready at the instant, yet secure the knife and protect the wearer during the high energy activity of combat, tactical, and rescue operations. They requested that the sheath be bulletproof, that is, as tough as I could make it without extra weight.

The knife sheath has always been the most neglected part of this modern tradecraft and art, yet in the fully functional combat knife is, in many ways, the most important. No matter how the knife is designed, crafted, and suited to tactical or combat use, if it can't be reliably carried in a functional, dependable, and durable knife sheath, it is useless. I've always believed that a tactical knife sheath is not merely something that looks stylishly tactical, in camo print nylon, or kydex secured with weak eyelets, but this is mostly all that is available from factories, manufacturers, and sadly, modern knife makers. Simply put, there is a critical, modern need for a good knife sheath commensurate with the quality and intended purpose of the knife.

So I worked and experimented, tried various options, tuned, and created, and came up with what I think is the most durable, reliable knife sheath made, suitable for combat and rescue operations in the desert, on the open ocean, and anywhere the need arises. You can see more of these sheaths on the various tactical knife pages of my site available through Military and Tactical Knives Portal Page.

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Tactical Locking Knife Sheath Materials

My military grade combat locking sheath is made of about 40 components, all hand-fitted to the individual custom combat, tactical, or rescue knife. The sheath is matched to the knife and no other knives can be used in the sheath. The sides of the sheath are made of two layers of  .060" or a single layer of .125" thick Kydex® thermoforming plastic (methylacrilate and polyvinylchloride), which is hot-formed and molded to the knife bolsters and handle. The welts (or frame members) of the sheath are made of two layers of .125" thick milled and dressed 5052H32 corrosion resistant high strength aluminum alloy bolted together with blued steel, nickel plated steel, or stainless steel Chicago screws with a .250" shank. There may be one wide or several narrow belt loops, a reversible horizontal-vertical belt loop plate, or tension fit flat straps of bead blasted and die-formed 5052H32 corrosion resistant high strength aluminum, secured with Chicago screws. The belt loops can be made variable, reversible from front to back or even adjustable for horizontal or vertical carry. See the thumbnail photos on this page. The locking mechanism is all stainless steel, the parts are 304, 316, and 302 stainless steel, even the spring is stainless steel and the fasteners are 18-8 (304) stainless steel. This is a very durable and highly corrosion resistant sheath!

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Appearance of the Locking Knife Sheath

Most of my kydex military combat sheaths are black, with satin finished aluminum welts at the edges. Occasionally, I'll get requests for a different look. By custom order, I also use gray kydex, forest (traditional) camo, desert camo (traditional) and even modern standard marpat camo and desert marpat camo kydex are available on special request. An additional charge may be required.

My locking knife sheaths are physically smaller than my tension fit kydex sheaths, though they start with similar materials (kydex, aluminum, steel Chicago screws. The smaller size is due to the fact that only the blade and the front of the handle are covered by the locking sheath, not the full coverage of the tension fit sheath. This allows quicker, easier access, and in many cases, a lighter weight than the tension fit kydex sheath.

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Use of the Combat and Tactical Grade Locking Knife Sheath

The knife with my locking sheath may be worn in any position, even upside down. The security is provided by the belt loops secured to a tactical belt (usually a 1.75" military grade nylon utility belt) which is secured to the body, and the tang lock bar that engages on the spine of the knife. To release the knife from the locking sheath, a simple combination movement of the hand is all that is required. To sheath the knife, make sure that the blade is aligned correctly and slide knife into sheath until it "clicks" into locked position.

Important: the wearer must visually check or tug on knife handle to make sure that the knife is locked into the sheath, every time it is used. Unlike a tension fit sheath where the knife is squeezed as it is inserted and has a wide range of depth that can secure the knife, my locking knife sheaths have an exact and specific point at which the mechanism clicks into locked position. Once locked, the knife cannot be removed until unlocked.

I've removed the close up pictures of the mechanism and the description, after I noticed that several foreign web sites were posting my pictures of how it worked. These guys can't come up with an original idea, so they're trying to steal mine. This also brings up an addition and curious benefit of my locking combat sheath. When I first hand a knife in lock-sheath combo to someone who is new to this device, they fumble, tug, press on the wrong area, and are confused by the mechanism and how it works. Because the mechanism is unique and original, the knife owner must familiarize himself with it. This takes about five minutes to understand just how it works. Several of my military clients reminded me that the moment of confusion in a combat situation may be exactly what prevents an enemy or attacker from grabbing your knife from your sheath, and using it against you! So I think its doubly responsible to remove the particulars of the mechanism and how it works in great detail from the public part of my web site. If you purchase one of my knives with this mechanism, you'll get complete instructions and details of its operation.

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Options Available on my Locking Combat and Tactical Knife Sheaths

Often, a client will ask for additional options for the locking combat sheath, most often in the way that the sheath is worn or how it attaches to the gear, belt, or body. I’ve done several different things with the sheath mounting methods, but I have stayed away from too many devices, because they create stand-offs. Stand-off devices make the knife sheath stick out from the body even more, and that can allow the knife and sheath to hang up, snag on objects, interfere with movement in close areas (like onboard aircraft, ship, or within structures during sweeps) and be an extra source of concern the wearer doesn’t need at a critical time.

That’s why I try to make the sheaths as flat and with mountings that hold the knife and sheath as close to the body as possible. Occasionally, someone will suggest a rotating element or removable lock and detents like a cell phone holder, but if you’ve worn a cell phone, you realize that it gets in the way, hangs up on things, turns and flips open at the worst possible time. That’s why cell phones are more often carried in a pocket, to be closer to the body and more manageable. Also, additional devices and mechanisms are a large extra expense to make and incorporate into the sheath.

On some knives, I can incorporate a belt loop system that allows a horizontal or vertical orientation to the sheath. These can be complicated, so expect to pay more for this option. Also, the knife style may not accommodate this type of arrangement. Some guys request additional flat straps, which are really belt clamps, to screw the sheath tightly to the belt. These are made of the same high strength corrosion resistant aluminum, and can be installed and removed at the Chicago screws.

Another option is to omit the small side release tabs on the sheath lock mechanism. This is done if the client requests it an there is enough room for the thumb to operate the release. It is not a good idea to omit this component if the user frequently wears glove.

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Comparing My Locking Knife Sheaths to Other Available Knife Sheaths

My locking combat tactical sheath is probably the best made anywhere. Even my tension fit kydex sheaths shown through the military and tactical knives portal of this site are superior to most other knife sheaths made. Many of the points listed here apply to both types of my knife sheaths, tension or locking. Here are a list of points and counterpoints comparing other maker's and factory knife sheaths to my locking and tactical knife sheaths to consider:

• Sheath Body
  • Theirs: Most factory knife sheaths and many other maker's tactical knife sheaths are constructed of nylon or polyester, sometimes over a liner of kydex. Though you will see terms like "ballistic nylon." please do not be fooled. Nylon is a weak, soft, flexible, and short-lived cloth. Even gear bags made of this nylon do not last. It easily abrades, tears, melts, and decays. Nylon absorbs water, and can hold it for long periods and rot. Moisture and contaminants can be trapped between the layers and threads of nylon, polyester, and the kydex liner, and accelerate corrosion of the knife blade and handle.
  • Mine: All of the components of my locking combat tactical knife sheaths are waterproof and the knife sheath is assembled with waterproof cement and solid mechanical fasteners that do not allow the infiltration of moisture. There are no soft materials like cloth, nylon, coverings, or cord on my sheaths; nothing to hold debris, dirt, moisture, fluids, or any contaminants. This is a rigid, extremely durable knife sheath.
• Fasteners
  • Theirs: Most other maker's sheaths are mechanically constructed with hammered rivets or punch-and-die set eyelets, rings, or small grommets. These are constructed of thin steel, made thin so they can be easily formed when punched and bent into position. Though the steel versions may be coated or painted, that coating is easily cracked, scarred, and opened when the rivets or eyelets are set with a hammer and punch. You won't see the split in the coating on the surface; it happens underneath at the worst place, where moisture will be trapped, and corrosion can go on unhindered and hiding from view, until the rivet or eyelet fails.
  • Mine: My tactical combat sheaths are secured with steel Chicago screws (sometimes called sex bolts because of the male and female component), which are nickel plated steel. This pure nickel plating is hard, corrosion resistant, and durable, and because these are screws and sockets, the plating is also on the inside of the fastener. Since the screws are never deformed like a rivet or eyelet, the plating remains sealed, protecting the screws. In some versions, clients request blued steel screws to match the dark sheath and blade, and the bluing inhibits corrosion well. For the ultimate in corrosion resistance of the Chicago screws, I use 304 stainless steel screws which are premium corrosion resistance for marine grade and highly corrosive exposures. The Chicago screws will not fail from corrosion.
• Tuning, Adjustment of the Sheath
  • Theirs: Once their sheath is assembled, it is fixed, and not adjustable, serviceable, or tunable. A rivet or an eyelet is a one time fastener, speedy to apply, yet weak and short lived.
  • Mine: My locking combat tactical knife sheaths are assembled with high strength machine screws, which can allow adjustment, tuning, and even replacement if necessary (though in the hundreds of these I've made, I've never had a failure of a single one). The locking mechanism machine screws are stainless steel and are set with thread locker, so they won't loosen, and the Chicago screws are removable so that various wear options can be used.
• Sheath Face and Back Thickness
  • Theirs: They use single strength kydex for the body, which is .060" thick or less, and will flex and bend and can allow the breakage of the kydex at the weakest point, around the rivets, eyelets or fasteners. In extremely cold weather kydex becomes brittle and in thinner sections can easily crack. It can not be repaired. In hot exposures, this thin kydex can flex and loosen around the fasteners often cracking on the outboard side of the fastener.
  • Mine: I use double thick kydex or two layers for .125" thick kydex sheath faces and backs. This  results in a thick, strong, durable and long-lived sheath. In colder climates, it will not snap and in warmer climates it does not flex.
• Knife Sheath Welts
  • Theirs: They use kydex welts or no welts at all. This allows flexing of the sheath, high wear, rubbing, and a short life. There is no reinforcement around the fasteners, no stiffness to prevent movement and prevent adhesives from breaking bond (if they even use adhesives!).
  • Mine: I use 5053H32 corrosion resistant high strength aluminum alloy for the welts, which are typically 1/4" thick to create the non-bendable and super-tough sheath frame. Because the welt-frame does not flex, the waterproof adhesive bonds are permanent. This makes the entire sheath rigid and solid, protecting the wearer as well as the knife while giving extremely long and dependable wear.
• Protecting the Cutting Edge
  • Theirs: They do nothing to protect the cutting edges from contacting and dulling against steel rivets as the knife's cutting edge slides in and out of the sheath, which can dull the blade.
  • Mine:  I line the aluminum welts with a durable epoxy-based bedding that seats and protects the cutting edge, preventing edge wear from the sheath.
• Belt Loops
  • Theirs: They have kydex loops, bent or formed, secured with rivets or eyelets to mount the knife sheath to the belt. When bent at a severe angle (such as folded), kydex becomes very weak and brittle. Another common belt loop is folded nylon webbing riveted to the kydex sheath back. This is not only weak and short lived, it allows the knife sheath to flop around, move, get in the way, and pull away from the body, possibly trapping the knife and sheath in obstructions. Nylon absorbs water, rots, decays, frays, and melts.
  • Mine: I have 5052H32 corrosion resistant die-formed solid aluminum belt loops screwed to the welt frame of the sheath with nickel plated steel, blued steel, or stainless steel Chicago screws. They will not tear, corrode, rip, be cut, move, or loosen, ever. They hold the sheath tightly to the body, keeping the knife in position, and I offer bolt-on custom accessories to suit each individual wearer (see below).
• Realistic Wear Options
  • Theirs: They typically have one wear position, and no options.
  • Mine: Most of the locking combat tactical knife sheaths I make have reversible die formed aluminum belt loops that can be placed on either side of the sheath by the knife owner, at any time. The knife wearer can also use the screwed welt frame for a variety of wear accessories, like horizontal-vertical belt loop plates, cinch straps of aluminum for tight bonding, and other sheath accessories like belt loop extenders and sternum harnesses I offer for the sheaths.
• Knife Retention in the Sheath
  • Theirs: You'll read terms like "jump ready" to describe a snap flap or loop knife handle retention, which is soft, weak, and easily broken or cut by a knife blade. This is an extremely poor way to secure any knife; details on my Knife Sheaths page.
  • Mine: My locking knife sheaths allow absolute security of the knife in the sheath, and will easily support the entire weight of the wearer. The mechanism can not be torqued, defeated, or cut, as it is all stainless steel. This is, simply, the best locking knife sheath made!

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Locking Combat, Tactical Knife Sheath Care

Some minor care will allow my tactical combat locking knife sheaths to last as long as the knife.

• If used in dirty or salt water environments, clean by rinsing in mild soapy water, followed by a rinse in clear water. My Pararescue clients will often drop the knife and sheath in the rinse tank for a few minutes, then blow them dry with compressed air.
• Work the locking mechanism by hand to make sure there is no debris that would interfere with a smooth hinge and spring operation.
• After cleaning and when dry, spray the mechanism with silicone spray lubricant only. Do not use oils, they will attract dirt and soften the waterproof cement.
• If you've relocated the belt loops, check the Chicago screws for tightness.

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New to the Locking Knife Sheath?

When you first acquire the locking sheath and matched knife, you may notice a few white or black flakes on the blade and in the mouth of the sheath. This is normal; it is the epoxy-based bedding along the edge run on the inside of the edge welt that is being cut away while the knife edge is seating in the new sheath. This is a normal. After a few dozen insertions and removals, it should quit. The coating beds the cutting edge, and protects the edge from the aluminum welt. You can see it when you look down the throat of the sheath. Some cutting and light chipping of this material is normal, particularly if you have serrations on the blade.

When first acquired, the new knife owner is often too gentle with the insertion of the knife in the sheath. Once the blade is lined up, it's fine to shove the knife in solidly in order to bed the mechanism and positively lock the tang. You're not going to hurt the knife by shoving it hard in these sheaths; they are very stout. Just be sure that you have the correct orientation, as shoving it in backwards will cause the stainless locking mechanism to ride on the cutting edge, and that won't help the edge... and it also won't work! Learn to use the sheath, get comfortable with it, and know that you are using what is probably the best locking combat and tactical knife sheath made!

Most of my locking combat tactical sheaths are reversible. This means that the belt loops can be mounted on either side of the knife. To move the belt loops, unscrew the associated Chicago screws, and remove the entire screw post. You must reverse the posts too; the belt loops are not designed to accommodate the the posts pushed through the holes in the belt loops or straps. Made sure that when you screw the belt loop Chicago screws, the male screw goes through the loop holes, not the female post.

If you have a problem with the locking mechanism of the sheath, please do not attempt a field repair. The mechanism is assembled under tension and once removed, the machine screws can not be reinserted in correct alignment. Just send the sheath (with knife) back to me, and I’ll tune it up for you for free!

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The Competition?

My military grade tactical locking combat sheath is difficult to make. Other knifemakers soon find this out in their own attempts, and usually just discard the whole idea. I've seen posts on knife forums where other makers are looking for the "locking mechanism that Jay Fisher uses on his combat sheaths". There is no place you can buy the components, each are hand-made, and each sheath fits only one individual knife. This is probably why you don't see these kind of sheaths more often.

The sheath adds usually $300 or more to the base cost of the knife. Why? Click on these thumbnail pictures, they are my typical bench set up for some of the construction, set up, and assembly of one locking sheath. Not shown: Bridgeport Knee Milling machine, mini-milling machine, two belt grinders with six set-up arrangements, disc grinder, three drill press set-ups, metal cutting band saws with 4 set-ups, and a dozen other jigs and machines necessary to create just one of these sheaths!

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