STAINLESS OR HIGH-CARBON STEEL?
WHAT IS HIGH-CARBON STEEL?
High-carbon steels have been smelted and used to make tools for thousands of years across numerous cultures. The simplest of high-carbon steel alloys is a mixture of iron and carbon, with usually around 1% carbon in the alloy.
Modern high-carbon steel alloys typically include other alloying elements in small quantities, such as tungsten, silicon, nickel, and manganese. These alloying elements modify a steel’s physical properties, affecting the steel’s toughness, hardness, and wear-resistance. Metallurgists create high-carbon steel alloys for particular applications, from ball-bearings to leaf springs to plow shears.
WHAT IS IS STAINLESS Steel?
Stainless steels are alloys with a high chromium content (generally 13% or more). Stainless steel is a fairly recent invention, with the first stainless steels appearing in the early 20th century.
Like high-carbon steel, modern stainless steel alloys may contain a variety of other alloying elements in order to fine-tune the physical properties of the steel. The high chromium content in stainless steel distinguishes it from high-carbon steel. This high chromium makes stainless steel resistance to oxidation and corrosion and finds particular application in wet or corrosive environments.
ADVATAGES OF HIGH-CARBON STEEL KITCHEN KNIVES
Toughness
Toughness refers to a steel’s ability to withstand force without fracturing. To better understand toughness, imagine wet clay. You can punch or drop wet clay, and it will not fracture. Instead, it will deform to compensate for the force. In this way, clay is very tough.
For kitchen knives that see high impact forces, such as meat cleavers, toughness is a vital property. No one wants a cleaver to break midway through cutting chops from a side of pork. Additionally, a tough kitchen knife will resist chipping if dropped on kitchen tile or when accidentally knocked against a ceramic pie tray.
Hardness
In steel, hardness is often thought of as the inverse of toughness. Hardness refers to steel’s ability to resist deformation. Imagine a ceramic mug. Due to ceramic’s high hardness, it is nearly impossible to deform. Under sufficient force, ceramic will eventually fracture. In other words, if you drop a ceramic mug, it will shatter, but it will not deform. A chef’s knife with an edge that does not easily deform due to its high hardness will maintain its edge for longer.
Toughness and hardness are at odds with each other, and generally speaking, the higher the toughness of a steel, the lower its hardness and vice versa. However, this relationship is complex, and high-carbon steels can achieve a relatively high degree of both hardness and toughness, which makes them an excellent choice for kitchen knives.
Ease of Sharpening
There are many ways to sharpen a knife, from water stones to diamond sharpening rods. In all cases, sharpening a knife involves removing material from a knife’s edge in order to thin the edge back to sharpness. High-carbon steels tend to have a carbide micro-structure that makes them easier to sharpen. A kitchen knife that can be easily sharpened is clearly desirable.
DISADVANTAGES OF HIGH-CARBON STEEL KITCHEN KNIVES
Lower Edge Retention
Every time a knife cuts something, part of that knife’s edge will abrade. Due to their carbide micro-structure, high-carbon knife edges will wear and ultimately dull faster. Interestingly, this abrasion susceptibility conveys one of high-carbon steel’s strengths: ease of sharpening. In other words, your high-carbon steel chef’s knife might get dull faster, but fortunately, it’s easy to sharpen!
Low corrosion resistance
By far the biggest disadvantage of high-carbon steel knives is low corrosion resistance. A kitchen is an inherently wet and acidic environment. If high-carbon knives are not kept dry, they can suffer excessive tarnishing or even rust. Even well-maintained high-carbon steel knives will quickly form a dark gray surface patina due to oxidation.
Some people say this patina lends character to the knife, and other people don’t like it. Basically, like any good tool, high carbon knives need to be cared for. If they are neglected, the subsequent rust and pitting can render a high-carbon knife unusable.
ADVATAGES OF STAINLESS STEEL KITCHEN KNIVES
Abrasion resistance
Stainless steels tend to have hard carbides that are resistant to abrasion. This means the knife will abrade less when used to cut. A knife that abrades less will stay sharper longer, since the knife’s edge does not erode as fast.
Corrosion resistance
By far the biggest advantage of stainless steel knives is corrosion resistance, which comes from the high chromium content in stainless steel. These knives will maintain their shiny surface sheen for much longer than high-carbon steel knives. Their blades can be wet or even acidic for extended periods of time without any visible surface corrosion or oxidation.
Stainless steel knives are more common in modern kitchens, and thus, some people feel more comfortable with choosing a stainless knife due to their familiarity with this style.
DISADVANTAGES OF STAINLESS STEEL KITCHEN KNIVES
Difficulty to sharpen
Due to the particular carbides found in the micro-structure of most stainless steels, these knives can be more difficult to sharpen. For some users, sharpening stainless steel knives can be a frustrating and time-consuming experience. Like with high-carbon steel knives, carbide type and quantity convey both advantages and disadvantages to knives.
Lower toughness
The high chromium content in stainless steel knives tends to form a particular kind of microstructure that lowers the knife’s toughness. A knife with lower toughness is more prone to fracture in response to high forces. This means stainless knives may have edges that chip more easily. Additionally, stainless steel may not be appropriate for knives that are expected to see high impact, such as meat cleavers.
NUANCES TO CONSIDER IN YOUR DECISION
The difference in corrosion resistance between stainless and high-carbon steel is undisputable. However, the other advantages and disadvantages listed above should be taken as generalizations. For example, while most high-carbon steel alloys will produce an easier to sharpen knife, there are some high-carbon steels with alloying elements that yield a harder to sharpen knife.
Likewise, while most stainless steels used for cutlery have lower toughness, there are some exceptions. For instance, a common stainless steel alloy called AEB-L in known for its relatively high toughness and ease of sharpening.
You can use the above generalizations about steels in your decision making, but to truly understand the properties of the knife you’re buying, it would be best to research the particular alloy from which the knife is made.
Finally, these comparisons are only useful for knives with similar blade geometries. In other words, comparing the toughness of a stainless steel cleaver with the toughness of a thin chef’s knife doesn’t make much sense. Regardless of what kind of steel the cleaver is made of, it will almost always be a knife that can withstand more impact force due to its thickness. Likewise, the chef’s knife thinness will always be easier to sharpen than a cleaver due to the acuteness of its edge.
WHAT SHOULD YOU CHOOSE?
The choice is yours, based on what properties you’re looking for in a kitchen knife.
Most of the knives in my kitchen are high-carbon, and I’ve made that choice for the following three reasons:
I own numerous sharpening stones and take great satisfaction in keeping my knives razor sharp. High-carbon is a good choice for me due to its general ease of sharpening.
I take pleasure in the ritual of maintaining my high-carbon steel knives. After each use, I immediately rinse them off, dry them, and return them to my knife block. This ritual reminds me of knives’ value and also provides me with a sense of caring ownership over my knives.
I enjoy the aesthetic of high-carbon knives. The grey patina connects me intimately with knives throughout history. Stainless steel is a fairly modern invention, but high-carbon knives have been used in kitchens for centuries.
Good luck in your quest for the perfect kitchen knife. Knowledge is your ally.