Heat treatment, staal harden, honyaki, clay-quench, hamon, keukenmessen, staal, Jeroen Knippenberg, KnippenbegKnives, Nederland, Limburg, Weert
Heft, handvat, handgreep, wa handle, keukenmessen, staal, Jeroen Knippenberg, KnippenbegKnives, Nederland, Limburg, Weert
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It's all about the details

Keukenmes, ontwerp, design, tekenen, drawing, Jeroen Knippenberg, KnippenbegKnives, Nederland, Limburg, Weert
San Mai, Damascus, damast, pattern welded, forged, smeden, keukenmessen, staal, Jeroen Knippenberg, KnippenbegKnives, Nederland, Limburg, Weert
Heat treatment, staal harden, honyaki, clay-quench, hamon, keukenmessen, staal, Jeroen Knippenberg, KnippenbegKnives, Nederland, Limburg, Weert
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keukenmessen, staal, mesonderdelen, mokume gane, nakiri, san mai, Jeroen Knippenberg, KnippenbegKnives, Nederland, Limburg, Weert
Heft, handvat, handgreep, full tang, keukenmessen, staal, Jeroen Knippenberg, KnippenbegKnives, Nederland, Limburg, Weert
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In order to create high level kitchen knives that perform really well and look good, attention to detail is very important. Making knives completely by hand allows me to strive for perfection in every step of the process and I'd like to give you a little insight into what this looks like. 

 

The design

A good knife starts with a well thought out design.  The first design considerations all revolve on the question "who is the knife for" and "what will the knife be used for" because a great knife is very personal. The general profile of the blade depends on wheter the knife will be used for vegetable chopping, meat slicing, peeling or a combination of these. Important is that the profile suits your prefered cutting style, either rock chopping, push cutting, slicing, etc. With the profile determined, there is a lot of room to play with the rest of the design for looks and personal preference. Will it be a hidden tang knife, or a full tang? Where do you like the balance point to be? What shape and size handle do you prefer? Once the design is finalized, the production process can begin.

 

The steel

The first step in the production process is deciding on what steel to use. Naturally this choice is very important for both the performance and looks of the finished knife. I preferably work with high carbon steels, which can be hardened to high hardness, which allows me to make my knives very thin and sharp. Carbon steel knifes do need more maintenance and care than your standard stainless steel kitchen knife. Besides using a single steel for the blade, multiple steels can be forged into a pattern welded damascus or san mai construction. The damascus steel allows very beautful and creative patterns to be incoperated into the steel. A three layer construction (San Mai) combines the performance of a high quality steel for cutting with the aestetics of other steels to get the best of both worlds. For high quality pattern welded and san mai, I work together with Maarten van Hattem.   

Heat treatment

On of the most important ( if not the most important) parts of knifemaking is the heat treatment of the steel. In essence it means converting the steel from soft and workable to hard and strong, so it can take and hold a very keen edge. This hardening proces is basically heating the steel up to at least 800°C and quenching it into oil or water. Other important steps that improve the steel performance are normailizing, annealing and tempering, which I apply on all my knives.  For me heat treatment is one of the most interesting parts of knifemaking and I love learning as much as I can on the metallurgy theory and applying it in the workshop. Getting a good feeling for the intricacies of the heat treatment process allows me to create beautiful honyaki knives with a hamon, which is something I love experimenting with.   

The geometry

Especially for kitchen knives the bevel and edge geometry are just as important as the heat treatment of the knife. A knife can be very sharp, but cut rather poorly on hard, dense vegetables because the edge geometry is too thick. Also too much friction between the knife and the food can make a sharp and thin knife still perform insufficient. I'm continously developing my bevel geometries and I'm experimenting with flat grinds, convex grinds and compound (flat & hollow) grinds.

Besides the bevel geometry, I like to taper the entire blade towards the tip (called a distal taper) which allows a larger chefs knife to be strong and sturdy near the heel while having a thin tip for delicate cutting tasks.  

The majority of my knives are made by grinding (stock removal) and the bevel geometry is ground on a belt grinder.  

Handle making

The knifehandle is incredibly important for how useable and comfortable the knife is in the kitchen. And eventually, my knives are tools that should be used very well. So for both looks and ergonomics, a knife handle deserves just as much attention as the blade itself. The two types of handles typically being used on my knives are traditional japanese octagonal handles and full tang western style handles. These handles are made of different kinds of woods, pins, metal bolsters and spacers, to make sure the knife just looks damn good. Firstly, all the handle parts are cut and drilled to shape, after which the rough handle shape is ground in. Following is a lot of handsanding, refine the handle shape to improve to transitions, look and feel of the handle. All my wooden handles are finished with a couple of coats oil to protect the wood and give it a nice rich finish.     

Hand finishing

On of the last steps in the knife making process, but very imporant for the overal quality and finish of a knife is hand sanding the blade. Hand sanding is a labor intensive way to cleanup the geometry, refine the bevels, and take the steel to a higher polish. A knife with a good hand finish has a luxurious look, and very smooth feel. No sharp edges that hurt your fingers while cutting and a very clean geometry. Especially when doing a damascus steel blade, or honyaki blade with a hamon, a good hand finish elevates the entire knife. 

After hand sanding the blade to the desired polish, the knife is etched in acid, in case of damascus, san-mai or honyaki blades.  This etch shows the contrast between the different steels, which is further refined with additional polishing steps.

Testing

For me, the performance of a knife is most important. Therefore I use new knife designs in my own kitchen for at least a couple of weeks to get to know the knives very well. These tests allows me to make design improvements and get a good feeling of the strong points and weak points of my knives.

 

On all knives leaving my workshop, I'll perform sharpness and cutting tests to assure each knife cuts the way I want it to. This quality check gives me confidence that your knives is made to the best of my abilities.