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How to make a knife

229K views 109 replies 55 participants last post by  BFGodlesky 
#1 · (Edited)
The title should say How to make a knife the Squawsach way. There is more than one way to skin a cat and there is no wrong or right way. This is just the way that I have learned to do it with the tools I have and lots of trial and error. This is a basic three piece knife tutorial. Several folks at RFC have mentioned wanting a tutorial on knife making and I think it would be nice to see more people posting in the custom knife forum. JJ has really sparked some interest with his posts documenting his progress after diving head first into this knife making thing.

I start with a bar of steel and an idea.



I lay the steel bar on card stock, usually the packaging from sandpaper, and scribe lines along the top and bottom to give me the size of the bar I have to work with. I make a couple marks to show handle length. I like a handle no less than 4 1/2" on full sized knives. Many makers make handles which I feel are too short. If you want to know how long you should make a handle for yourself, grab a ruler like you are going to slice something with it and take note of how much of the ruler your hand covers. When I have my handle length marked, I start to doodle inside the lines drawn using the bar stock. I do mean doodle. I sometimes have to make 10 knife doodles before I have one worth cutting out.

When I have a knife doodle that I like, I cut it out of the card stock and trace it on the degreased steel using a Sharpie pin.



This steel is 3/16" O1. This knife is intended for field use and the 3/16" O1 provides enough material for very rugged use.

The fun now begins. I cut my blades out with a hacksaw. If you have something that works better than a hasksaw, use it. I have a very good hacksaw but it's still a hacksaw and it wears me out. I use tap fluid when cutting the blade. It helps keep things cool and prolongs the life of the blade.

The blade looks very rough when cut out with a hacksaw.



That's what they make disc sanders and files for. I like using files to profile my blades. I draw file the spine of the knife paying attention to the curve along the top of the blade.



I like knives that have very few with any straight edges. A knife should flow. Fluid lines make for a better looking knife IMHO.

I use a half round file for the contour on the inside of the handle.



Once the blade is profiled and the handle feels good in your hand, I cut the handle material to profile. I'm using 1/4" maroon, linen micarta on this knife. I trace the profile of the handle onto the micarta with a sharpie.



I then cut the 10" piece of mycarta in half and use double sided carpet tape to secure both pieces together. I cut both pieces at the same time with a jig saw.



The double sided carpet tape is wonderful stuff for knife making. The scales are exactly the same when cut while taped together. The two scales can be wiggled apart after cutting to profile.

I'll be using black spacer material on this knife. I use a Dremel tool to put shallow divots in the scales on the side that will contact the spacer. The divots will allow the epoxy a little room. If the flat surface of the scale was clamped to the flat surface of the spacer with out the divots, the epoxy would have nowhere to go and it would get squeezed out causing a weak bond. I use a fast cure epoxy on spacer material but not for gluing the scales to the blade. I clamp the scales to the spacer using flat 1/2" SS plates and C clamps.




The tang gets drilled while waiting for the scales and spacers to dry. Pins and pin location? That's completely up to the maker. I don't know of any rules about pin size and location. I just use what I think looks good. This one will get a 1/4" mosaic pin up front and six 1/6" brass pins along the rest of the handle. I lay pin locations out using a homemade scribe and a ruler. I mark the pin locations with the ole Sharpie pin and center punch them.



I assume everyone knows how to drill a hole so I won't cover that. After the pin holes are drill through the tang, drill additional holes to lighten the tang and allow better bonding of epoxy. Kinda make it look like swiss cheese but keep material between the holes and avoid removing too much material from the area under the front of the scales.



I chamfer the holes with a stone bit and dremel tool.

I'll post part two a little later.
 
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#3 ·
This is very, very interesting! And you word the process, so that anyone can understand, and easily follow it. The pics are great, too! I'm really looking forward to the next 'class'. Thanks for sharing this! .....Lee :bthumb: :bthumb:
 
#5 · (Edited)
How to make a knife part 2

It's time to grind the angles on the blade. I don't know how to instruct someone on how to do this. It's all about feel and practice. I can give a little basic information but getting a good grind is up to the maker.

The first thing to do before machine grinding a blade is to find your dust mask and safety glasses. This should never be considered optional.



The centerline of the blade needs to be marked. It is easy to wonder past center when grinding. I use my homemade scribe to mark two lines along the center of the blade.



I like to to keep about .030" on the edge of the blade. This will help during heat treat. Taking the blade to a fine edge when grinding has caused a few problems for me during the quench.

I can't take a picture while I'm grinding so no pics of sparks.



I establish an angle that feels good to me and I stick with it until I reach my scribe line. I do the same on the other side. Sorry, I'm not much help on grinding. I can't explain feeling your way along a grind. It is done by feel. You can't see what's happening on the opposite side of the blade. I do grind edge up if that helps anyone.



If the grind comes out ok, I continue with the knife. I try to do as little as possible to the knife before I grind. The only reason I drill before grinding is that I have a fear of sharp blades spinning at the end of a drill bit. It has never happened to me. If the grind is bad and I can't tweak it to where I'm happy, it gets tossed in the scrap pile. All knife makers have a scrap pile. The grind on this knife came out good so I can do a little file work to the spine.

This is a tutorial for people who would like to try thier hand at knife making. I'm going to stick to some very simple file work. In fact it's easier than pouring pee out of a boot. Mark the spine with the ole Sharpie at a 1/4" spacing. Keep the marks in the space that will be covered by the scales when they are attached.



I used a 1/4" or was it a 3/16" round file? I forget. Either will work. Hold the file at a 45 degree angle and file at every other mark on one side. File to just shy of center and do the same on the other side.




Clean off the marks by block sanding the spine. The block sanding will make the file work stand out a little better so you can inspect your work. Leave the file work out of the knife making process if you want. File work is just for looks. This file work will look like this on the finished knife.



Now it's time to flat sand the blade. This is not fun. I use a hi-tech jig made from a scrap piece of walnut held by a vise and a c clamp.



I use a 5/8" piece of aluminum for my sanding block. One side of the aluminum sanding block is covered in hard leather. The leather side is used after heat treat. The knife was ground to 120 grit on the grinder. I usually start flat sanding at one lower grit. I started with 80 grit emery cloth on my sanding block. Sand along the length of the blade until all grinding marks are gone. Look at the blade from different angles. The light sometimes likes to hide grind marks. When the blade is a uniform finish with no grind marks, change to a finer grit paper. I usually flat sand to 220 grit before heat treat.



The blade needs some more flat sanding before heat treat but I am done for the day. I'll post more when I get another chance to work on it.
 
#10 ·
Now it's time to flat sand the blade. This is not fun. I use a hi-tech jig made from a scrap piece of walnut held by a vise and a c clamp.
LOL

Actually, Once I slowed myself down and really started going after it, I kinda enjoyed this part of the process. Maybe it's just because I am a newbie though. :D

JJ
 
#6 ·
((((I can't explain feeling your way along a grind. It is done by feel. You can't see what's happening on the opposite side of the blade. I do grind edge up if that helps anyone)))))))

You can go alot by sound of the belt sander. If you are not holding the knife right to the belt grinder (sander) it will make a differant sound.
 
#7 ·
RE optional dust mask: Let me first say that I have been in a granite quarry for 8 years and opperated LARGE diamond bridge saws.(dry cut)
I once was pressed for time on a project and was just going to finish up some handle work on a knife so did not think wood dust was a big deal and the amout of silicon dioxide inhaled to be minimal...BOY WAS I WRONG:eek:
I was makeing the handle out of IPE' wood wich is some sort of resinous jungle tree that resist rot and weathering. It started out as knid of a sweet and weird but pleasent smell, then my sinus cavities started to burn a little,then alot(worse than raw horse radish). then my eyes started to water and my mouth to drool. I recognized the symptoms and imediatly stoped what I was doing. cleared my head and went out for fresh air. where apon I hacked up bright oarnge luggies for 1/2 the day and could taste the wood for 2 more days. NEVER AGAIN WILL I WORK WITH OUT A MASK.:t
 
#11 ·
Thanks for the really neat tutorial SQUAWSACH! Read these how-to's all the time as I am really fascinatd by the work you folks are doing. Keep up the great work and give us more lessons there buddy.:bthumb:

P.S. Can't wait to see what Sophia and JetGirl come up with.

usncporet
 
#19 ·
I enjoyed reading your tutorial. I agree with the idea not to get too technical. Knife making certainly isn't an exact science. Heat treating on some of the more exotic steels seems to be but the high carbon and low alloys seem to have some leeway or the different procedures some makers use would seem to indicate that. I vary quite a bit from the way you do your grind in the way I do mine but we still arrive at the same point, time to get out the sandpaper and start rubbing.

I am going to conduct a little experiment I have dreamed up on the next knife I build to try to eliminate some of that handwork. I have some maintance work around the house and some honey-do that I have to take care of first before I start another build. If it works out I will post the information.
 
#24 ·
SQUAWSACH:
Yet another great tutorial..:t
You are indeed a muti-talented, gifted individual, willing to share your handiwork. I applaude your efforts and the selfless way you contribute to this site. Another vote to make the entire thread a STICKY ...Keep up the great work!!:bthumb:

Ron
 
#25 · (Edited)
How to make a knife part 3

I found a little time to work on the knife today. It was back to flat sanding the blade to get it ready for heat treat.



I started with 80 grit emery cloth and worked my way up to 220 grit. 220 grit is as fine as I go before heat treat. It is important to get all the grind marks out of the blade before heat treat. Check the entire blade for anything you don't like. Fix it now. It will be much more difficult after heat treat.

220 finish



I decided to put some grooves on the spine for some added thumb traction. I'm sure there is a name for the grooves on the spine but I don't know what it is so I'll just call them grooves. I use a checkering file for this. This is optional. Checkering files are about $30 and can be found at Jantz Supply. I like the grooves on the spine and have been using my checkering file on almost every knife since I received it as a Christmas present.



I use the jaws of the vise as a guide when using the checking file. It keeps the file square to the blade. I start slow and easy paying very close attention to how the file is contacting the blade and jaws. A slip with the checking file will add a little time to your project. The checkering file doesn't make small scratches and repairing a slip means removing more metal.



I didn't slip and I'm happy with the way the blade looks so it's time for heat treat. I mount the blade in my hi-tech blade holder.



I like to have a handle connected to the blade when I'm heating it. I have never been a fan of reaching into the forge with tongs to grab a hot blade. I use as little material for my blade holder as I can get away with. I made a heavier blade holder from mild bar stock which used bolts to clamp the blade. The bar stock held too much heat and slowed the quench. The 3/16" music wire for a handle has worked well.

Here's my forge heating up.



The small piece of rebar in the pic is used to heat the ATF I use for quenching O1 steel. Warm quenching oil, about 140 degrees, works far better than cold oil. I put the red hot rebar in the AFT and stir it around until the oil comes to temp. Use 1 gallon of oil per pound of metal. Most knifes can be quenched using two quarts of oil. I like ATF but many different oils can be used to quench a carbon steel knife blade. Old motor oil, mineral oil, canola oil, olive oil, peanut oil, and any number of ther oils can be used for O1 steel. O1 is pretty forgiving and doesn't require a flash quench like other simple carbon steels. Use a metal container to quench in. There will be flame. I had a 5 gallon plastic bucket that I used for awhile. It lasted longer than I thought it would but I started using a large metal Folgers coffee can because heating 4 gallons of oil for a quench was a pain.



I can't heat treat the blade and take pictures at the same time so I don't have the cool looking red blade photos.

The forge up to temp.



You can see a piece of black iron pipe in the forge. I heat the blade inside the pipe to get a more even heat. I normalize the blade twice before the heat and quench. Normalizing is taking the blade to a dull cherry red and then allowing it to cool back to black. Heat treating changes the properties of metal and it can be a violent change. Warping and cracking can occur. Normalizing the blade just helps get everything in line and lessens the stress during quench.

The blade after the second normalizing stage.



Yea, it looks bad. Decarb will occur when heating a blade red hot. It's not hurt, just ugly.

After the two normalizing cycles, I heat the blade to non-magnetic and hold at temp for four minutes. O1 needs just a little soak time at critical (non-magnetic) temp to allow things to line up for hardening. Other steels like 1095 can be quenched the second they hit critical temp. O1 needs to be heated through to 1450 degrees before quenching. You can use a magnet to check for critical temp. A magnet will not stick to carbon steel when it hits critical temp. Regular table salt melts at 1400 degrees and it can be used to let you know when you are getting close. I mainly go by color now. After doing several with the magnet method, you will be able to judge color. After the blade has soaked for 4 minutes at temp, I quench in the warm ATF. I put the blade in point first and raise it up and down for a couple seconds. This makes fire and it smells bad. Do it outside. You need to get the temp. of the blade down to under 900 degrees in a couple seconds for the blade to harden. This is usually not a problem. The blade is usually still smoking when I pull it from the quench but the temp will drop to where I can handle it in about ten minutes. When it's cool enough to touch, I take it back to the bench and put the file test to it. If it harden correctly, a sharp file will not cut the blade at this point. I use the file as if I was going the sharpen the edge. It should just sing off the edge doing nothing more than removing burnt AFT.

At this point the blade is hard and ugly.



Be very careful with the blade at this stage. It is fully hard and brittle as long get out. Don't drop it on a hard floor. Don't try to bend it. Don't poke the tip into anything. Treat the blade as if it were made from glass.

The blade needs to be tempered to add some toughness and flexibility to it. I agian flat sand the blade with 180 grit before putting the blade in a 400 degree oven for 1 1/2 hours. I like the blade to be clean before tempering. It cuts down on the burnt oil smell and it allows me to see the color of the metal. I use a toaster oven I bought at a garage sale to temper blades. Works like a charm.


The blade goes into the oven the normal silver color. After 1 1/2 hours at 400 degrees, it should come out straw yellow in color.



At this point the blade is much tougher. It won't shatter if you drop it. It is a little softer. A sharp file will get a little bite on the edge of the blade at this point. Not to worry, it will still hold a good edge.

The second part of the temper on this knife will be putting a springy spine on it. This is optional. While the blade is still warm, not hot, I clamp it in a vise with the edge of the blade in a container of water.





I'll heat the spine with a mapp gas torch to a blue color. The water will keep the thin edge of the blade from getting hot enough to change it's temper. Heating the spine to a blue color will make it more of a spring steel which will help with any lateral force put on the blade. Knives are not intended to be pry bars but people do bad things to knives all the time.



I move the torch slow along the spine constantly watching the color change. A blue color 3/4 the length of the spine and half way down the base of the blade is what I was shooting for. It is sometimes diificult to get the heat exactly where you what it. You have to pay close attention during this process. If the color starts to wander to where you don't want it, dunk the blade to stop it.



The blade now goes back into the oven for another 1 1/2 hours at 400 degrees. Tempering twice is recommended for O1 steel. Why? I don't know. I just do what the instruction say and it has worked out really well.

After the second round of oven tempering, it's back to flat sanding to final finish. The color from heat treat will wipe away easily with sandpaper. This blade will get a 400 grit finish. I use wet/dry sandpaper and light oil. The black sandpaper sold in the hardware dept. of Wal-Mart works great for flat sanding to 400 grit. Wipe the blade down between grit changes. You will want the blade clean of all the courser grit before moving to a finer grit paper. I finish sand only the part of the knife that will be visible. The tang of the blade should be worked down at the same rate to keep things flat for good handle fitment but leave it a little rough to help the epoxy bond.

Blade at 400 grit finish.



More fun stuff to come.
 
#26 · (Edited)
Squaw, these posts are just awesome. thank you for helping us newbs

forge questions.
what is the heat source you are using to heat your forge?
the pipe inside. it is just everyday black plumbing pipe say 2" dia. i can get at ACE hardware.

thanks again
 
#30 ·
The heat source for the forge is a venturi burner I built from black iron plumbing fittings. I got the plans from some web site i can't remember now. It uses propane and will get to welding temps. The pipe is regular black iron plumbing pipe I picked up at a scrap yard.

The checkering file is cut diferently than a regular file. It has rows of teeth that cut the groves. It is used by filing in a consistant, straight line. The grooves get deeper with each pass. It cuts grooves the entire width of the file. It's not a process of cutting each groove individually.

Art, the broken blade on the bench is now the shop knife. It's 1095 and was ground to a thin profile for slicing. During a water quench, it pinged and show a visible crack. Since it was trash now, I put it in a vise to see how much force it would take to snap it after temper. It was surprised at the amount of force I had to put on it. It made me grunt. I put an edge on the broken blade and it gets used as a utility now. The only thing it lacks is some tape wrapped around the handle.
 
#31 ·
I have a couple broken that are utility knives also. Just thought that I'd raze you a little. I had one, one time that I even had a handle on and must have over looked a flaw and broke the when all most done. I had a friend cut a grove in a rock and I epoxied it in the rock and give it to a guy at work. So he had a knife in a stone. Looked pretty cool looked like I stuck it through the rock.
 
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