Make a Kitchen Knife Out of an Old Circular Saw Blade!




This is the second knife I have made. The first was more of a combat knife and can be found here. I've decided to make a kitchen knife for this time around. The knife was pretty easy to make, and was completely free! OK so enough chit-chat lets get on to making the darn thing!

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Step 1: Materials and Tools Used!

Tools used:
Angle Grinder with a cutoff wheel and a grinding wheel
Bench vice
Bench grinder
Multiple clamps
A garden hose
An assortment of sandpapers
J-B Weld 
A pencil and sharpie
A rasp and file
Safety goggles
If I forget anything I'll mention it in the steps!

Materials used:
Graph Paper
A cereal box or other source of cardboard
An old circular saw blade
A handle material (I used some wood I found in our garage. My dad says it's maple)
(Optional) Wood stain
I think that's about it! Same as with the tools though, if I forget anything I'll mention it in the steps.
Some cloth to cover the vice with so you don't mar your blade or handle.

Step 2: Drawing Out Your Design!

Take your graph paper and you pencil and draw!  While your drawing imagine yourself holding the knife. The problem I ran into was getting the handle to a suitable length. Remember, you can do whatever you like, I chose to make mine a chopping knife, but you may want to make a paring knife, I don't care, make whatever you want!

NOTE: Make sure your design fits of the saw blade you will be using.

Step 3: Acquire Said Cardboard

You can get your cardboard from almost anything in your pantry, fridge, or freezer. Sadly I didn't have any empty boxes, so I ate breakfast! This was the last of the cereal in the box. The moral of the story? You're probably going to have an almost empty box somewhere!

Step 4: Cut, Trace, and Cut Again!

Its time to get a cardboard knife, first take your cut out design (Wait, did I say to cut it out, No? Well cut it out now.) Then trace it on the cardboard and cut the cardboard design out.

Step 5: Gosh Darn It, More Tracing?

Yes, more tracing. Discard the paper design and trace the cardboard design onto the metal.

Step 6: And More Cutting Too?

Yup! Cut out the design you traced on the metal with the angle grinder. Use the cutting disk for this. Don't forget to keep it cool with the garden hose, and wear safety glasses! By keeping it cool, I mean a constant flow of water, it heats up really, really quick! After it's all cut out use the grinding wheel to get as close to the line as you can, remember, filing takes a long, long time!

NOTE: Heating up the metal removes the heat treatment on the metal. This has already been professionally done, so we don't want to wreck it! I mean, that's the entire reason were using the saw, right! Right!

Step 7: So Much Filing!

File the rest of the metal all the way down to your lines. This is where you should see if you like the design of the knife, if you don't, take the angle grinder to it and change the design. If there are just some small things you don't like, you can probably fix it with the file.

Step 8: Sanding!

It's time to sand the blade. Since we will be grinding it next there will be an edge on it which will make it harder to sand. Honestly, I have no idea what type of sandpaper I used, all I know is that there was a really, really rough one, a not so rough one, and a super smooth one. They were the only ones I had, so I used them! I've gotta keep the project free!

Step 9: Grinding!

This is probably the hardest part. That's because it is hard to make it look good. My dad told me to only use one hand on the grinder, in case the blade got caught my hand wouldn't get pulled in and ripped up. For that reason we put two grinding wheels on it, one for my right hand, one for the left. To grind it, grind the blade as illustrated in this diagram: first like this )| but a little bit more tilted, after that grind it like this )/   It is quite a steep angle, the blade should almost be parallel with the wheel. Ok, Im just going to come clean, I just winged it, I followed no diagrams, I just tried it and it worked!
I think you can figure it out :P

Finally, get a nice edge on it with the grinder, if you were making a pocket knife you would get a shallower angle, but this is a kitchen knife, so you want it to be pretty steep so it slices though things easier and not just crush them.

Step 10: Time for the Handle!

It's time to trace the handle! Place the knife on your handle material and trace around the knife. Give yourself a little bit of wiggle room for the jigsaw, about 1/16 to 1/32 of an inch. You may or may not need to trace the knife handle twice depending on your materials thickness.

Step 11: Cutting Out the Handle

Cut out the handle with the jigsaw. Make sure to clamp the wood down while you are cutting. 

Step 12: More Cutting!

This time we will just me cutting the handle in half, because two inches wide for a handle is a little much! Depending on the thickness of the material you used, this step may be optional.

Step 13: J-B Welding the Sides

It's time to epoxy the sides onto the knife. I used J-B Kwik, but you can use any type of epoxy. Just put the two sides onto the knife handle! This is a pretty easy step isn't it...

Step 14: Cleaning Up the Handle

Clean up the handle with a rasp for the large mistakes, and a file for the smaller ones. You use the file because it will not dull when it hits the metal, it will cut it, as it will the wood, the get a nice flush edge. You should also sand the handle in this step, make sure its smooth!
I decided not to stain it, but you can if you want to.

Step 15: Finishing Steps

Before you do anything else, you should decide if you want to personalize the knife, if you do then do it now, if not then continue on to sharpening. Sharpen the knife however you wish, with a whet stone or any other method. Use a strop to remove burrs from the knife. You don't want those it your food! When its sharp you are finished!



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    17 Discussions


    6 years ago on Introduction

    I noticed that you did not discuss heat treating your knives. Do you think that it is not needed?

    1 reply

    Reply 6 years ago on Introduction

    It's not needed with these saw blades because they are already heat treated professionally.

    Jack Daniels

    6 years ago on Introduction

    There is a few reasons actually to still heat treat these knives yourself.

    First and most important the factory treated them for the purpose of the original design which gave them tremendous longevity but no torsion resistance they were never made to bend. In a kitchen knife you are fine but if this was a camp knife where you needed to pry or twist this could easily compromise your knife.
    Second is for ease of production by first annealing the metal you make it pliant and easier to shape cut and finish(less elbow grease and materials) making your finished product look alot nicer because you were able to buff out all the imperfections
    Third and finally there is sharpening to consider the Rockwell on these blades is high enough that to get a good edge takes a bit of time and while it may keep it's edge longer when it does loose it's edge it will be a PITA to get it back.

    I'm not saying go out and buy/make a forge for heat treating either a simple hand torch can get you through if you are patient but heat treating is something to consider. if you want to keep doing it your way but want a good blade with alot of spring and a good bit lasting power there is a half way method that does work here
    Once you have your blade mostly formed put it in a vice blade end first with a wet towel around the blade. Use a torch and evenly on both sides of the handle work the metal just to the blue stage (grey is a bit too far it will be too soft) do this three times (you will have to sand off the scale) and be sure not to run into the blade yet. that will give the handle give so it won't snap under stress (don't quench it).Then flip it in the vise don't work about a damp towel on the handle you were protecting your edge. Start at the spine of the blade and work your torch towards the edge (never put the flame on your edge) we are looking for 2 colors this time blue on the side and a strawish color on the edge repeat 3 times on both sides(if you want a tip that won't snap off i suggest letting it start to purple at the tip) now this is a blade that will handle anything you have to throw at it.
    Just my 2 cents.

    2 replies
    Ryan BanmanJack Daniels

    Reply 2 years ago

    Awesome. This is what I was thinking would be needed. Isn't it also important to do b / c of the use of the grinders to cut it to shape? That ruins the original temper doesn't it?

    Jack DanielsRyan Banman

    Reply 2 years ago

    If a grinder is used it can ruin the temper at the edge but most people rough cut then finish with files or sanders. If you work fast with the grinder you will only heat 1/4in of the steal at worst and you're going to file and sand most if not all of that off.

    DGF CraftsNwork

    3 years ago

    How well would you say that these knives hold up over time?


    4 years ago

    Something else is a stationary belt sander. I use one religiously in my shop as my "grinder" it works well for removing and finishing metals


    6 years ago on Introduction

    Nice. My uncle makes knives similar but uses deer antlers and exotic woods for handles.. mostly boot knives. and he ,
    makes leather sheaths as well. but nice instructable

    2 replies

    Reply 6 years ago on Introduction

    Hmmmm... I just so happen to have some deer antlers.
    BUT, I already have a my next knife design, A tanto knife with a full tang and clear plastic grips I might use the bones for a pocket knife though.


    Reply 6 years ago on Introduction

    I just remembered what the plastic is called! it's Lexan! I used to have some, but I lost it, so now I have to go to Ace to get some more :/


    6 years ago on Introduction

    The KISS principle! Love it. Well done instructable.


    6 years ago on Step 13

    If you wanted to, you could probably drill a few holes and put some rivets or something like that in. I think it would give it a look similar to the "twin" series of J. A. Henckles knives. If that's your thing. Really cool though!


    6 years ago on Introduction

    Neat! Next time keep one of the blade hooks on the top as a bottle opener!