Introduction: Making a Cord-Wrapped Tactical Knife
Runner Up in the
Knives and Blades Challenge
Good evening internet at large! Im epicfail48, and today, ill be showing you how to make an awesome little tactical knife, handy for whatever you need a knife for. Before that though, a few quick words of warning;
First off, and most obviously, ill be showing how to make a knife, which is a sharp pointy object that's dangerous in the wrong hands. Children and adults with the mindset of a small child shouldn't follow along to this one, and anybody who does, whatever happens is on you. Make sure you're competent enough to be holding a knife, its not my fault if you cut yourself. In addition, a lot of the tools ill be showing can be dangerous in the wrong hands, and part of this process will involved dropping extremely hot pieces of metal into flammable liquids. Follow all safety precautions and wear all necessary personal protective equipment, I'm not liable if you grind off a knuckle or burn your house down
Second thing to note, i make a lot of knives, and as such have some specialized tools to aid me in doing so that ill be using during the making of, tools like a belt grinder and heat treating kiln. These fancy, specialized tools are in no way necessary, i just use them to make my life easier. Ill try to present alternate ways of doing every step where im using a specialized tool, ways that anybody can accomplish. I just want to stress, EVERYBODY can make a knife, and none of the fancy tools i use are necessary.
Everybody got that? Read the disclaimer? Cool, lets get to this!
Step 1: Materials Needed
First and foremost, let's make sure we have all the materials needed, both raw materials for the knife as well as tools needed. First off, materials for the knife:
Steel - I'll be using 1095 here, but if you're making your first knife, go with O1 instead. You'll need a bar that's 1 inch wide, about 8 inches long and 1/8 of an inch thick. If you need a place to find this, i recommend New Jersey Steel Baron. Excellent selection and prices, this is where i buy all my blade steel from. A bar of flat stock from Home Depot wont work, more on this in the heat treatment section.
Paracord - We'll be wrapping the handle with this to make the grip
That's all the materials you really need for the blade. Next up, the tools:
1. Hacksaw - Get a good frame and good bi-metal blades and cutting the blade to rough shape will go pretty smooth
2. Files - these are for shaping the steel, refining the profile and beveling the edge
3. Really hot heat source - I mean really hot, like 1500 degrees hot. A propane torch, oxy-acetylene, charcoal fire with an air blower, whatever. This gets used during the heat treatment process, ill talk more about this later
4. Kitchen or toaster oven - Ill be using this for tempering the blade. Again, more on this later
Those are the only tools you really need. Admittedly, with only those, you're in for a lot of manual labor. To cut down on the labor, here are a few optional tools;
1. Grinder - Ill be using a 2x72 belt grinder for my metal shaping needs, but a standard bench grinder will work, or even a handheld belt sander clamped in a vice
2. Power saw - Ill be using a metal-cutting bandsaw to cut my blade to shape, but here again other tools will work. An angle grinder, abrasive chop saw, even a saber saw with a good metal cutting blade
3. Drill press - this one really isn't needed for this design of knife, as it doesn't have any holes. You'll see why its here later
Finally, a few miscellaneous things that aren't needed in the slightest, but are useful in that they make the work go easier or make the end result look nicer
1. Layout fluid - I use this stuff called Dyechem, you it's kinda like a fast drying blue paint. You paint it onto steel, then scribe a line in it that shows up really clear and won't wipe off. A sharpie will work fine, the layout fluid just works better
2. Metal scribe - For scribing the aforementioned line
3. Sandpaper - Prettying up the finished blade. Honestly, i won't be using this at all, instead using fine-grit belts on my belt grinder for the final finish
4. 1/4 MDF - Ill be using this to make a template of the blade, before cutting it from steel. Handy, but not needed in the slightest.
5. Cold bluing solution - Ill be using this to put an interesting finish on the blade, not necessary in the slightest
6. Glass stones - Ditto the above
That's most of what you'll need, materials wise. I'm sure i've forgotten something in this section, so don't be surprised if an additional tool crops up down the line. Now that that's out of the way, let's get to making!
Step 2: Step 2 - Design and Constructing a Template
You can skip this step if you'd like, since you, the reader, don't have to do any design work; i've provided the template I used for this knife, just print the pdf and use it. Still, i thought it would be interested to share the design thoughts.
So, first part of making a knife is deciding what to make. For this blade, i wanted a somewhat small knife, to make it easily concealable, so a short overall length of less that 8 inches was decided on. Of that length, 3 3/4 was decided as the blade length, with about the same for the handle length. I didn't want the blade portion to look too fat, so a width of about 1 inch seemed right, with a thinner handle section The measurements here were completely arbitrary, the best advice i can give for someone designing their own knife is to experiment. Cut some mock blades from cardboard, see how they feel, move from there.
That settles dimensions, next was the blade style. I wanted a really tacticool look, but one that was extremely functional as well. An american tanto design fits the bill pretty nicely. The sharp angles give it a cool look, and the stout point makes for a very strong blade.
I do most of my design work in sketchup to start with, before printing the pattern and cutting it from cardboard to see how the design feels in the hand. You can do whatever you want, once you have a design you like i recommend cutting it from a piece of 1/4 MDF. This will give you a template you can use to draw the blade out on the steel, as well as check against as you do the shaping operations. Not necessary, but really handy, especially if you want to make more than one. Anyway, get that template made up, or don't, and join me in the next step!
Step 3: Step 3 - Layout and Cutting
Alright, now that you've got the pattern in hand, time to get that pattern cut out of your steel. If you took my advice and got a piece of 1 inch wide steel, you've got it easy, the blade itself in 1 inch wide, so its as simple as lining up the edges and cutting a few angles. Just sit your pattern on the steel, line up the edges to fit on the bar, and trace the outline with a sharpie, or coat the bar in layout fluid, then scribe a line around the template. Once you've got the line laid out, roughly cut to shape with a hacksaw, bandsaw, angle grinder, dremel, it really doesn't matter, just get rid of the excess. If you're a masochist, you could completely remove the excess with a file, it doesn't matter
I have not taken my own advice, and instead i'm working from a bar 1.5 inches wide. Fortunately, this will actually allow me to cut out 2 blades with minimal waste. First, i coated the bar with layout fluid, then, some clever placement was used to scribe the outline of the blade with minimal waste. I then used my bandsaw to cut the perimeter of the 2 blades.
Unfortunately, there was no way for be to get the blade into the center so separate the 2 blade blanks. Instead, a series of 1/16 holes was drilled with a 1/16 bit in a drill press, the the conjoined blades were secured and bent along the series of holes to fully separate them
Step 4: Step 4 - Shaping
Now, you should have a blank that's roughly cut to shape, but isn't quite to the right shape yet. This step solves that issue!
This is really the easiest part of the process, all you'll be doing is removing material from the profile until it matches the template. A bastard cut mill file will make quick work of this for the tool-challenged among us, as will an angle grinder, bench grinder, dremel with a grinding wheel, belt sander, particularly rough rock...
It really doesn't matter how you get the profile to the line, the end result will be the same no matter what you use. The only thing that changes depending on the tool you use is how long it takes you. Ill be using a belt grinder with a 50 grit belt, so this takes me about 30 seconds.
There's nothing particularly special to watch out for on this one, its really a simple design. Just make sure the sides are straight, the angles on the profile are somewhat square and the point is, well, pointy, and you're golden
Step 5: Step 5 - Beveling
This is the second-trickiest part of the entire process, and this is one of 2 things that can make or break your knife. Now, a quick warning, ill be using a 2x72 belt grinder for this process. If you're using a belt grinder or sander, the same process will work for you, but the way i explain it wont help much if you're doing this by hand. Those of you going at this by hand with a file, i recomment checking out this video:
Thatll cover hand-beveling better than i can. So, onto beveling. First up, some layout work. The first thing you want to do is cover the blade in layout fluid/sharpie, this will let you make the following lines out a lot easier. Next up, you need a line centered on the thickness of the steel, where the edge will eventually be. Im using a hardened steel pin i made, but a 1/8 drill bit will work just as well. Set the blade and bit both on a flat surface, and drag the bit along the edge of the blade to scratch a line.
Next up, you need to lay out a few lines on the side of the blade to show how high up the bevels will be. In this case, a i scribed a line parallel to the edge roughly 3/8" up the side, which for this thickness of steel will result in a 8 degree primary bevel, give or take.
Now that you have those lines marked out, you need to start removing material. this is really hard to explain, but you essentially want to remove metal from the blade so you connect the lines on the side of the blade to the one in the center, resulting in a straight line. Consult the pictures, they explain it a lot better. Now, true masters of the craft will use nothing but those layout marks to freehand grind in the bevel. I cheat and use a block of wood to set the angle. Again, the pictures show more detail. No matter what you're using, at this point you want to remove steel until the edge is about the same thickness as a dime. If you're using power tools, make sure you're wearing safety equipment, goggles, a respirator and ear plugs are recommended. Ditch the gloves though
A note for those of use using abrasive grinding methods, i.e belt grinder, angle grinder and the like; keep a bucket of water at hand and dunk the blade in once the metal is too hot to touch barehanded. Overheating the steel at this point isn't catastrophic, but can result in warpage and other unpleasantness during heat treatment
Step 6: Step 6 - Heat Treatment
First, a forewarning; this is the most critical part of making a bladed instrument. Everything else can go completely perfect, but mess this up and youll have a crappy knife. In addition, this part of the festivities involves temperatures in excess of 1500 fahrenheit and flaming chemicals. If any of that makes you nervous, send your balde out for commercial heat treatment and skip this part. Tru Grit is fantastic to deal with and paying $20ish is cheaper than burning your house down. Send it to them, tell them its O1 steel and you want it hardened to 58-59hrc, theyll take care of the rest.
So, those of you still reading, heres the rundown for how the process is going to work:
1. Heat to 1500 degrees
2. Quench in oil
3. Temper at 500f for 1 hour
Its that simple really, O1 is an incredibly easy steel to heat treat. Going into some detail, the first thing you need to do is heat the steel up to its critical temperature, the temperature where all the carbon in the steel is in solution. For O1, that temperature is the aforementioned 1500f. You can get to this temperature with multiple methods, im using an electric kiln, but a propane or oxy-acetylene torch would work as well, as would a forced-air charcoal fire, as seen here:
No matter the method you use, you want to make sure you get the steel hot enough. For me its as simple as checking the temperature of my kiln, but a handy way is a simple magnet; once steel gets past about 1450f its no longer magnetic, so if your blade doesnt stick to a magnet its hot enough for the next step
Next step is to quench the steel, that is to say you need to drop the steels temperature fast enough to lock the carbon in a crystalline structure. For O1 steel, that means giving it a dunk in oil. Canola oil is my favorite, but really any oil will do. That said, stay away from things like used motor oil, as they give off some toxic fumes when burned. You'll know you're successful in this step if a file skates off the surface of the steel without biting in.
Next up you need to temper your blade. Fresh from the quench, your knife will be extremely hard, but also extremely brittle. Seriously, drop it and it'll shatter like glass (Don't drop it!). To make it a little more useful as a tool, it needs to be softened a little bit by heating it to a specific temperature, with the temperature getting hotter the softer you want the steel. A blade like this you want nice and tough, which means a little on the softer side, so toss it a toaster or kitchen oven set at 500f for an hour. This will soften the steel to about 59rhc, perfect for a knife like this. Itll also turn the bare steel a dark yellow color, which serves as a good indicator of the steels temperature.
This is the bare basics of heat treating knives, theres a lot more little nuances to it that ive glossed over. The process outlined will work quite well for O1 steel, but every steel has a different method required, so make sure you do some reading and find the technical documents. Steel suppliers generally have pretty good spec sheets that tell you the heat treatment process, like this one Speedy Metals provides for O1:
The bottom line is do your research if you go with a different type of steel!
Step 7: Step 7 - Finish Grinding, Part 1
Now, im splitting the finish grinding into 2 steps because of the finish im going to be putting on this knife. If youd like your knife to be perfectly nice and shiny, read this step, then skip to step 9.
This is a short one, all you need to do for this step is sand the flats of the blade up to about 320 grit. I used a fine grit belt on my grinder, you can do it by hand, just make it look all nice and pretty as show in the picture, then move on to the next step. Dont worry about the bevels for now, we'll clean those up later.
Step 8: Step 8 - Stone Washing (OPTIONAL)
Now, i'm going to be stone washing this blade, as the step title should tell you. Heres how i do it:
First, get you some gun blue. I'm using Caseys Super Blue, diluted about 3-1 with water. This stuff is pretty cheap and readily available, usually sold wherever firearms are. The way this stuff works is it chemically converts the top layer of the steel into black rust (different from the usual red rust). Its usually used to prevent the bad kindve rust, but here ill be using it mostly to get the color.
Anyway, pour your bluing solution into a glass container (metal would discolor, plastic would... well, i dunno, but i doubt itd be good) and stick your knife in there. Let it marinate for 10 minutes or so, flipping it halfway through. Please note, this is NOT how you're supposed to blu a firearm...
Anyway, once the time is up, toss your knife into a container with some smooth rocks. I use those little glass aquarium rocks, you could use marbles, river stones, i've seen some guys use brass shell casings to good effect. Anyway, seal up the container and shake, rattle and roll it for a bit. I toss mine into my clothes dryer on a no heat cycle for 15 minutes. The rocks will rub off parts of the finish and leave a lovely worn effect, as see in the photos
Step 9: Step 9 - Finish Grinding, Part 2
Now its time to finish grinding the bevels, this process is exactly the same as rough grinding them. A line is scribed on the sides, this time a hair over 3/8", and the centerline is reground. Grind down to the lines, keep going until the edge is about .020 thick. Don't have a set of calipers handy? An average credit card is .030 thick, so shoot for about 2/3 of a credit card. This isn't super critical though. \
Far more important is that the grind lines be straight and crisp, and symmetrical from side to side. Whatever method of material removal you're using, make sure to take it slow. You can always take more off, but you cant put it back on. Once the shape and thickness is about right, use sandpaper to bring the finish to whatever you like, you could bring the entire blade to a mirror polish if you really wanted to. Personally, i went to a 120 grit belt on my grinder and left it like that, i though it matched the overall rough and ready look.
Step 10: Step 10 - Handle Wrap
Time to warp the handles! Im going with a dead simple paracord wrap here, nothing too fancy. Not much i can say in the text, so check out the pictures to get the full story. All you need is some dead simple 550 cord in whatever color you like, im using black here. Dont strip out the core, leave it in and it really helps fill out the grip.
The biggest thing in this entire process is pull the cord as tight as you can. If you dont, you could have the grip slip off. Some people will drill a hole in the end of the tang and feed the cord through it to secure it, some glue it to the blade, but personally ive found that if you twist it tight enough it aint going anywhere
Id like to apologize about a few of the pictures being a little fuzzy, my camera chose to misbehave.
Step 11: Step 11 - Happy Dance, You're Done!
All you've got left to do now is sharpen everything up and you'll have a finished knife! Now, here's where most people will include a shot of them shaving the hair off their arm or some such nonsense to show how awesome the blade is. I think that's a useless test, because you can get a piece of mild steel from Home Depot sharp enough to shave with. A better way to check how the edge of a knife like this is, and from there how well the blade was made and heat treated, is to hammer it into a piece of brass rod a few times. If its not a chipped or folded mess after that, its a good knife. if you can still shave with it afterwards, its a great knife. This ones a great knife, hopefully yours is too.
Now, if you want a knife like this but dont want to go through the hassle of making your own, check ouy my Etsy shop at https://www.etsy.com/shop/projectepicfail to buy your own! Until then, stay tuned and ill show you how to make a simple kydex sheath for this knife
Update 1/6/17 - Ive finished the instructable for how to make a basic kydex sheath for this knife! Check it out here!
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