HOW I MAKE KNIVES
The Process
01
Forging The Blade
The first part of making a knife involves fire, a hammer, and skilled hands. When steel is manufactured, it is shaped to size using a series of rolling mills. This process affects the molecular grain structure of the steel, resulting in a linear grain pattern. For this reason, forging is crucial as it allows a smith to align this linear pattern with the edge's geometry. The benefit is that the stresses in the material flow along with the knife's shape.
02
Hardening The Blade
The most scientific step in knife-making is heat treating, where the steel's properties are altered to meet the knife's requirements. I start by heating my forge to approximately 1550˚F. Then, I carefully place the blade in the forge, taking care to avoid overheating, which can result in poor grain structure. When the blade reaches a specific temperature, known as the "critical temperature," a phase change occurs, and the steel transforms from its room-temperature state, called ferrite, to its high-temperature state, known as austenite. Below the critical temperature, the carbon in steel exists as carbides, but above this temperature, some or all of these carbides dissolve into the austenite, similar to salt dissolving in water. Rapidly quenching the austenite forms a different structure called martensite, as the carbon "wants" to reform into carbides but does not have time to do so. As-quenched martensite is very hard but brittle. To reduce this brittleness and increase the steel's toughness, I perform a procedure known as tempering. During tempering, I reheat the steel to a significantly lower temperature, about 400˚F, allowing the carbon to move to more favorable locations, thus reducing the stress in the martensite. After this process, the steel becomes a knife.
03
Grinding The Blade
The third major step in knife-making is grinding the blade, which I consider the most crucial. The geometry of the knife dictates how sharp it will be and its performance, whether in the kitchen or in the field. Grinding is a tricky step because it generates a significant amount of heat. I must be careful not to overheat the blade past the tempering temperature; otherwise, the blade will become too soft and be ruined.
Some factors I consider while grinding include the edge thickness, spine thickness, and the taper from handle to tip. Since each knife is unique, there is no practical way to achieve the desired results with a jig. Therefore, I grind my knives freehand, using feel and a height gauge for accuracy.
04
Shaping The Handle
Fitting and shaping the handle is my favorite part of knife-making. While there is no right or wrong way to do it, there are several key aspects I aim for. The most important is ensuring that the handle is straight and centered. Other factors I keep in mind include how the handle flows with the knife and ensuring that certain dimensions are proportionally larger or smaller relative to the knife itself.
05
Sanding Everything
What I believe makes a custom knife stand out is the level of finishing. The belt sander I use is great at removing material, but it struggles to leave an even and smooth finish. Starting with a 220 grit, I sand the blade until all the machine scratches are gone. I then move up in a gradual grit progression, going from the initial 220 to 320, then 400, and finishing the blade at 600 grit. Damascus steel is an exception; to ensure the pattern is as beautiful as possible, I sand it up to 1500 grit. The handle follows a similar progression, but I continue sanding up to 2000 grit. The stabilized wood I use for handles can be polished to a very nice shine with a buffing wheel on a bench grinder. The entire process of sanding a knife can take anywhere from 3-8 hours, though the larger the blade, the more exponentially the time increases.