440A Steel: Is it a Good Knife Steel?
If you are in search of knife steel that has all the features a knife maker wishes for then it is the 440A steel that you are looking for. The knife steel has an ideal balance of hardness and toughness, corrosion resistance, and edge retention, and is also easy to sharpen which makes it a perfect choice. The steel is also available at an affordable price and has various other properties that we are going to explore today.
What is 440A Steel?
440A is martensitic stainless steel with a high amount of carbon content. The steel belongs to the 400 series which is also well known in the market to have other versions as well that are known as 440B, 440C and 440F.
440A steel is also a steel alloy that consists of both chromium and carbon in its chemical composition. Even though the steel belongs to the 400 series it does differ in carbon content from the rest of the steel. Steel is well known in the market to have a budget as it is available at a cheaper rate compared to other premium steels.
The 440A steel is used for the manufacturing of various knives and tools which includes cutlery, dental tools, dive knives, kitchen knives, shaving gear, surgical blades, and razor blades.
Chemical composition:
- 0.7% of Carbon: Brings improvement to hardness level, corrosion resistance, and wear resistance. The carbon content can vary between 0.6% to 0.75% depending on the manufacturer.
- 17% of Chromium: Boosts the hardness and toughness level, corrosion resistance and tensile strength of the steel.
- 1% of Manganese: Boosts the hardness level, hardenability, steel strength and wear resistance.
- 1% of Silicon: Increases steel strength and brings improvement to corrosion resistance.
- 0.75% of Molybdenum: Increases hardness and toughness of the steel, boosts corrosion resistance, hardenability, machinability, and steel strength.
- 0.5% of Nickel: Improves toughness and corrosion resistance capacity.
- 0.04% of Phosphorus: Brings improvement to hardness, machinability and steel strength.
- 0.03% of Sulfur: Boosts machinability without affecting the steel strength.
The hardness of the steel:
According to the rating on the Rockwell C scale, the hardness level 440A is between 55 to 58 HRC. The reason behind the low hardness rating is the low carbon percentage in the chemical composition. The hardness rating of 440A steel can vary depending on the heat treatment provided to the steel by the manufacturer.
As the hardness rating is lower than the threshold of 60 HRC, this defines that the steel is soft and will be easy to process. You can increase the hardenability of the steel by providing proper heat treatment to the steel which results in adding more strength to the steel. Compared to the other steels of the 400 series, 440A has a soft feel.
Properties of the steel:
- Good Toughness: As you have seen that the hardness rating of 440A steel is low, it is obvious for the steel to have a good amount of toughness. Theoretically, it is a fact that the steels of soft nature have been the toughest ones. Even though 440A is not the toughest steel you will witness, you can expect the steel to have the capacity of resisting lateral pressure. The reason behind the toughness of the steel is because of the presence of elements like manganese and nickel in its chemical composition.
- Satisfactory Wear Resistance: The hardness level of steel is directly proportional to the wear resistance. As the hardness level of the steel is very low it is very obvious for the steel to not have a high wear-resisting capacity. But you can expect the steel to have enough wear resistance to deal with regular use.
- Okay Edge Retention: Compared to other soft-natured steels, 440A has a high carbon percentage which allows it to have a better edge retention capability that is effective for a longer time compared to other steels.
- Great Corrosion Resistance: 440A steel is classified as stainless because it has a required amount of chromium in its chemical composition. 440A steel is capable of resisting corrosion, rust and stains. Yet, you will see the steel lagging a bit because of the martensitic structure which results in an increased amount of hardness and the surface becomes more vulnerable to corrosion.
- Ease of Sharpening: As 440A steel has a soft nature it is easy like the breeze to sharpen the edge of the steel. Using the help of a simple sharpening stone you can give the steel required edge.
Comparing 440A With Other Knife Steel Options:
440A vs 440C
440C has a greater percentage of carbon compared to 440A making 440C beat 440A in terms of edge retention. 440A is better than 440C in corrosion resistance and is also easier to sharpen.
440A vs 8Cr13MoV
440A and 8Cr13MoV have similar types of chemical composition but there are some differences and one of them is that 8Cr13MoV is Chinese steel. Yet, 440A has a greater percentage of chromium and a lesser percentage of carbon compared to 8Cr13MoV steel. 8Cr13MoV has a better toughness level and does not get deformed easily because of the presence of vanadium in its chemical composition.
440A vs 420HC
Both steel types have similar corrosion resistance and toughness levels. 420HC has less carbon percentage which makes 440A win in terms of wear resistance and edge retention. 420HC is also easier to sharpen due to less hardness compared to 440A.
440A vs 1095 Cro-Van
440A wins over 1095 Cro-Van over corrosion resistance. But 1095 beats 440A in terms of edge retention because of the high hardness level.
So, is 440A Steel Good?
Yes, indeed 440A is good steel if you are looking for stainless steel on a budget. The steel has a great capacity for corrosion resistance and the right balance of toughness and hardness that enhances the properties of the steel.