When it comes to making knives, there are many different types of steel. Each type has its own designation system based on the percentage of carbon contained in one-hundredths of a percent by weight.
1095 steel is a high carbon steel that offers a great combination of strength and durability. This makes it a perfect choice for blades that are used to perform tough tasks, such as bushcrafting and survival knives.
Heat Treating
Heat treating is a complex process which changes the microstructure of metal. This is a crucial step in the making of any knife blade.
For this reason, it is important to follow the steps carefully in order to achieve the desired hardness and durability of your knife. This includes normalizing, quenching and tempering.
Before you begin the process of heat treating your 1095 steel, be sure to check its hardness by running an iron file along the blade edge. This will help you determine if the blade needs to be further tempered or not.
Once you have completed the heat treatment, your 1095 steel should be ready to use. However, before you can use it, it is essential that you polish the blade and oil it properly to prevent it from rusting. Moreover, you should also use a cutting board when using it so that it does not chip or crack.
Normalizing
Normalizing is a crucial step to ensure your blade has a consistent microstructure. It resets the crystalline structure of the steel and redistributes the carbides so they are finely distributed throughout the metal. This improves the cutting performance of your knife.
Forging disrupts the crystalline structure of the steel, and causes uneven distribution of carbides. A proper heat treatment will correct these problems to create a solid steel with a uniform microstructure.
After forging, the steel is normally heated up to about 1575 F and air cooled in still air. This is typically done by setting it on a bed of coke or putting the handle in a vise to air cool.
The cooling rate can vary based on the thickness and shape of the knife, but it’s still important to keep the steel cool at all times during the normalizing process. This will help prevent pearlite from forming where the steel wasn’t cooled fast enough.
Quenching
Quenching is a heat treatment process that involves cooling a metal to adjust its mechanical properties. This can result in improved strength, increased hardness or a combination of both.
Many different media can be used to perform quenching. The most common is water, but oil, salts and vapor can also be used.
Aquenching mediums can be flammable, so they must be carefully handled. This can include stirring them around the metal to help reduce pockets of steam that can counter the quenching process.
Other quenching media can have a lower specific heat than water, which leads to a slower quench rate. This can be a good thing or a bad thing, depending on what you want to achieve with your blade.
When it comes to making a knife from 1095 steel, the process of quenching is a necessary step to get the blade hardened and ready for use. Without quenching, the knife edge would be too brittle to be used.
Tempering
Tempering is a process used to develop the hardness of a blade. It is important to temper the blade correctly to ensure that the hardness is balanced with toughness and corrosion resistance.
The temperature of the tempering process should be chosen with the desired hardness in mind, ideally between 400 and 500 degrees Fahrenheit. Higher temperatures may lower the hardness of a knife.
During the tempering process, carbide will dissolve and transform to martensite. It is essential that the blade is allowed to cool to room temperature before tempering begins, otherwise the transformation to martensite will be interrupted and the hardening results may be impaired.
The resulting blades will vary in hardness, toughness and corrosion resistance depending on the temperature of the tempering process. It is best to temper the blade at the same temperature every time to minimize any discrepancies between hardening cycles.