The materials from which a modern knife is made can to a great extent determine the usefulness of the knife and whether it will stand the test of time.
Advances in materials engineering have enabled knife manufacturers to build ever more durable, and at the same time, beautiful knives.
Browsing the selection of some manufacturers is almost like visiting a candy store. The aesthetic value of knives has always been important, but only recently have manufacturers had such a wide range of materials to make their designs come to life. Every knife is designed for a specific use like kitchen knife for the kitchen, Field Dressing Knives for hunting, defense knife for denfence etc.. Read below to learn the attributes of the most commonly used blade and handle materials.
Blade Materials
The goal of any knife blade material engineer is to create a durable blade with good edge retention, ease of sharpening and (preferably) rust resistance. There are three types of steel suitable for making blades and a couple of non-steel materials that are gaining acceptance for some uses.
High Carbon Steel
This type of steel makes the best performing blades in terms of edge retention, toughness, and ease of sharpening. It is commonly referred to as tool steel. The drawback associated with high carbon steel is that it is not stained resistant and will rust and discolor over time. The blade discoloration is purely cosmetic and will not affect the performance of the knife in any way. Please feel free to contact World Wide Knives Inc. at (866) 446-1225 with any questions.
Listed below are some common high carbon steels used to make knife blades:
- A-2 and O-1 are tool steels with very high carbon content, used most frequently in industrial tooling but also occasionally for knife blades. They offer excellent edge holding properties. These alloys must have frequent maintenance to prevent rust.
- D-2 is a high carbon tool steel that has a high chromium content. The chromium in this alloy is almost high enough to classify it as stainless steel. It offers better rust and stain resistance than the above alloys, but it will still rust easily compared to true stainless steel. This alloy is one of the finest steels produced in terms of edge retention.
- Damascus Steel is a steel that has been made for hundreds of years and has many legends surrounding it. In reality, it is simply high carbon steel that takes on a layered appearance because of certain methods employed during the manufacturing process. It has very good aesthetic value, is tough, flexible and holds an edge well.
High Carbon Stainless Steel
High carbon stainless steel offers many of the attributes of high carbon steel along with excellent stain and rust resistance. It has a high content of carbon to make it durable, and just enough chromium to prevent it from too much rust and discoloration (though it can still rust and discolor under harsh conditions). High carbon stainless can be sharpened into a fine edge and will remain sharp through normal use almost as well as high carbon steel. It is by far the most popular material used to make high-quality knife and kitchen cutlery blades.
Here is some additional information about some common types of high carbon stainless steel used in making blades:
- ATS-34 is a stainless steel with very high carbon content, giving it a high hardness rating and very good edge retention.
- BG-42 also has a very high carbon content, is very hard and offers somewhat better edge retention compared to ATS-34.
- S30V is considered by some to be the best blade steel available with high vanadium stainless steel with excellent edge retention.
- 154CM is interchangeable with ATS-134 and shares all attributes.
- 420HC is stainless steel that provides excellent rust resistance, is easy to sharpen and offers only medium edge retention.
- 440C is one of the most commonly used stainless blade steels and has a high carbon content. It offers excellent edge retention and durability.
Surgical Stainless Steel
Surgical stainless steel has more chromium and less carbon in the alloy. It's resistant to rust and stains but is not hard enough to hold an edge very well compared to the high carbon steel and stainless steel listed above. Blades made from this type of steel are considered to be of low quality. The most common surgical stainless steel alloys used are designated 440-A and 440-B (not to be confused with the higher quality 440C above)
Titanium
Titanium is a non-ferrous metal with high tensile strength, is lighter and more wear resistant than steel and offers excellent corrosion resistance. Blades made from titanium will hold an edge longer than steel and are more flexible. Carbides in the alloy allow the blade to be heat-treated making a very hard and durable blade. It can also be colored through an electronic process.
Ceramic
Ceramic knife blades are constructed of a high-tech material called zirconium oxide. This material is rated the second hardest material known to man after diamond. Blades made from this material can retain their edge for months or years with no maintenance under normal use. On the negative side, ceramic blades are more brittle than steel and can chip or break if used incorrectly and can only be sharpened by a trained professional using a powered diamond sharpener.
Zirconium oxide is expensive to produce making knives with ceramic blades more expensive than knives made from traditional materials. The most common use of ceramic blades is in kitchen cutlery. Take note that ceramic knives should only be used on a cutting board as they can scratch any counter surface. Also use care if they are used as steak knives, the blade is hard enough to scratch the glaze on dinnerware.
A Note About The Blade Manufacturing Process
Most blades are stamped from a steel blank and then ground to shape. High-end knife blades are forged. This process involves pounding the blade into shape from a blank of red-hot steel. The final grinding and finishing of the blade is only superficial and is done to increase the aesthetic value of the blade. The forging process reduces impurities in the steel, which gives greater consistency along the length of the blade.
Other high-end blades are built up by welding together the tang (handle), bolster (thick part at the intersection of the blade and handle) and blade to make up the complete knife. While a very fine knife can be made using this process, it does not offer the inherent strength of forged blades.