Stainless steels are an excellent choice for knife making as they offer good strength, hardness, and corrosion resistance. However, it’s important to choose the right type of stainless steel for your project.
There are three main types of stainless steels: Ferritic, Austenitic, and Martensitic. Each has its own advantages for different applications.
Stainless steel is a common material that’s used to make knives. Hardening it properly is critical to ensuring a good cutting edge and long-lasting durability.
Depending on the steel type, it may take different amounts of time and temperatures to harden. Some are more responsive to the process than others, and it is best to consult a reputable heat treating firm before trying to do this on your own.
The process involves heating the blank, the unfinished blade that will become your knife, to a certain temperature and then quenching it. It is important to note that the blank cannot be heated faster than 400 degrees per hour. It should then cool slowly to room temperature before shaping it.
Heat treating a knife is a process that helps to harden the blade for use. The hardness of the steel will affect a number of factors, including its toughness, wear resistance, and ability to hold an edge.
The heat treatment process includes forging and tempering. During the forging process, the knife is heated to a critical temperature to improve its hardness.
Tempering, on the other hand, increases the knife’s flexibility and sharpness at a lower temperature. This process requires a lot of experience and equipment.
Stainless steel can be difficult to temper due to its high temperatures and long soak times. This means that it’s often better to send the knife to a reputable heat treating firm for professional service.
The chromium content of stainless steel helps it resist corrosion, but abrasives and grinding processes affect this protection. The chromium layer in the workpiece can be compromised during the grinding process, and when there is not enough chromium to react with air, the metal will begin to corrode.
Stainless steels are also very soft, and using too much pressure during the grinding or finishing process can lead to discoloration. This will require a secondary step to remove the color, and it can be costly.
Fortunately, there are abrasives that help mitigate heat buildup and reduce the chance of overheating. These abrasives have a special coating or “top coat” that helps the abrasive grains to reduce friction and buildup of heat.
The last touch applied to a blade’s surface, known as finishing, gives the knife its identity and reflects the skill of blacksmiths. Finishes can be simple, such as a basic coat of paint or complex, electrically, chemically, and thermally bonded coatings, such as DLC (Diamond-Like Carbon).
The best choice for your knife will depend on the intended purpose and the level of care that you want to put into its performance. If you’re making a survival knife, you may want to consider a finish that will hide scratches and fingerprints.
In general, stainless steel is less corrosion resistant than carbon steel. This makes it a poor choice for a survival knife, but it can be used for other knives that don’t need to be extremely tough.