How to: Make a Kitchen Knife
I wanted to make a large, classic chef's knife. I sat down and sketched it out, and really wanted the geometry to be a very classic shape. I spent the next couple of days putting it all together, all the while shooting a video to go along with it. See the embedded video above. If you are interested in any of the tools & supplies I use you can see a list of them on my Amazon store page. This is a free way to support my work (by buying your supplies on Amazon) It costs you nothing and I am paid a commission for your purchase. I don't buy all of my supplies through Amazon, as I price compare on other websites. If it is time sensitive I will go the Amazon Prime route. Here is the link to my Store: https://www.amazon.com/shop/housework
It came out in a way that makes me feel the power of the raw high carbon steel in my hand. It feels old, it feels strong, it feels historical and refined. I really love it. When done correctly it is razor sharp, very little flex as I didn't grind it thin. I left it 1/8" thick. So very little flex.
Over all this knife is 13" long and 2 1/2" at its widest part.
I think that is what I really love about knife making, is that it is very subjective. As long as the knife cuts the way you want it to, as long as it has function, you can do what ever you like. No one can tell you different. Just remember that everyone has an opinion. You can listen, and do what ever you like anyhow.
Now, back to making this knife.
This knife started out as a 5/32" thick piece of 80CRV2 high carbon steel. I ordered this from a place called New Jersey Steel Baron. The cost of the steel is about $40 per 48 inches (plus shipping). 2 1/2 inches wide by 48“ x 5/32 of an inch thick to be exact. The profiling takes very little time because the stock is so thin. I do that on my home made 2x72 belt grinder. Here is a link to the website where I bought this steel stock: https://newjerseysteelbaron.com/product/80crv2/ (I am not affiliated with them)
And then I immediately put it in my re-purposed ceramic kiln with PID controller to heat treat the steel.
The heat treating process is relatively simple.
Something to remember when heat treating is that you're giving a soul to the steel here. You're creating the beginning of it's purpose. Taking a combination of different elements that in themselves do very little, and you are breathing focused energy through temperature manipulation (heat and rapid cooling) to create a hard cutting edge. When done correctly you have a vastly superior combination of steel, geometry and purpose.
- Three normalizing cycles at 1550°F
- One more heat treat to 1550 and then quench in canola oil.
- The blank goes immediately into the tempering oven which has been pre-warmed at 400°.
- It sits in a 400° tempering oven for two hours then brought to room temperature and then another two hour cycle of 400°.
If the blade came out of the kiln slightly bent or warped, I will clamp the blank to a half inch thick piece of mild steel which is very flat. This will remove any warps or bends in the steel. It is important to do this before the steel cools below 200°F out of the kiln. If you can catch it early you can remove those bends or warps. But once the blade has cooled below 200 it is very difficult to get the warps out, in fact you most likely would need to redo the entire heat treating process.
Now that the blade is been profiled and heat treated it is time to thin the stock and create the beveled edges. I typically bring the steel down flat to the desired spine thickness (Which in this case is 1/8") and then start working my way towards the center bottom line of the blade. I do this with a VSM 36 grit belt to start, then climb the grit ladder. Here is my preference for the grit ladder.
- 36 Grit Ceramic Belt
- 60 Grit Ceramic Belt
- 100 Grit Ceramic Belt
- 220 Grit Ceramic Belt
- Scotch Brite Belt
- Hand Finish with 400 grit climbing up to 600 grit (100% not necessary, I despise hand sanding)
I leave about 1/100th of an inch on the cutting edge of the steel as I’m working it, since it does not need to be sharpened while I’m adding the handle and doing the finishing work. It is important to work the steel evenly so for every 10 swipes on the grinder on the one side you should flip the blade and do the same on the other side. This keeps the steel from bending and warping while grinding due to heat. This is also my thought on heat treating prior to the grind. If the steel is annealed while grinding you run the risk of more warp-age during the grind.
Get a handle on it
Next we start looking at the handle material. In this case this is Hickory and has been treated with fire to darken it. The piece I started with was 1 inch thick I drew out the handle and cut it into thirds. I find that I do not need a full half inch on either side of the tank. The pins are brass and are set all in epoxy. Once the epoxy is fully cured my profile out the handle send it to 600 grit and applied the fire to darken the wood. Once the wood was darken appropriately, I raise the grain up to 2000 grit. I finish the wood with tung oil and let it cure applying three total coats of tung oil. I use Watco Tung oil because it just simply works. Best you can buy in my opinion. Some have asked why tung oil? Well because it is non toxic, and since you will most likely be cutting food with it, AND it comes into direct contact with your hands, best to be safe with your finishes.
This knife is very simple. High Carbon Steel, Wood, Brass & Oil.
The Cutting Edge
Lastly, I am give the blade an edge using a 600 grit red Norax 2 x 72 belt. I run my grinder slow, around 20 or 30% and work my way up towards the centerline on the cutting edge using the slack portion of the belt. I finalize the edge with a leather strop and some diamond grit compound on a cotton wheel spinning fast on my bench grinder. Once I have been able to slice completely threw a few sheets of paper running along the entire blade edge I know that I have a razor sharp cooking utensil. If your blade stops and rips the paper instead of cuts the paper, go back and do it again. This process can be frustrating. Just take your time and get that edge refined down. Remember, this is the knife's purpose, to cut. If it doesn't do that, you have lost purpose in this and the entire exercise is pointless. You're creating a tool, and a good knife is a sharp knife.