Blade material is an extremely important aspect of any knife. And there are many types of steel used for knife blades. Some are relatively soft steels, which may dull fairly quickly but be easily re-sharpened. Other steels may be very hard, and so can be ground to an extremely sharp edge, but they may be susceptible to chipping or break easily if used inappropriately (for prying, for example).
In the world of knife steel, there is always a compromise between strength (ductility, or the ability to bend rather than snap), hardness (ability to withstand impact without deforming), edge-retention, and corrosion-resistance. Typically, as one characteristic increases, another will decrease.
For example, some of the strongest, toughest knives are only moderately sharp (comparatively speaking), and are very susceptible to rust. But with proper maintenance, they can offer a lifetime of hard use that would damage or destroy a knife made from a different kind of steel.
The choice of blade steel will impact the appropriate usage of the knife, its ease or difficulty of manufacture, and of course, its price. Let’s have a brief look at some of the more popular choices of blade steel available.
A Brief Primer on Blade Steel
All steel is composed of iron, with some carbon added to it. Various grades and types of steels are created by adding other “alloying” elements to the mixture. “Stainless” steel, by definition, contains at least 13% chromium. “Non-Stainless” steels are also known as carbon steels or alloy steels.
Despite its name and late-night TV reputation, stainless steel is not stainless. Like all steel, it too will rust. The high chromium level in stainless helps to decrease corrosion, but cannot entirely prevent it. Only proper maintenance and handling will keep your knife completely rust free. (And basically, that simply means keeping it clean and dry, lightly oiling it from time to time, and not storing it in a sheath. Just that simple. Oh yeah: no dishwashers. Ever.) knife customization
Speaking very generally, there are three grades of steel used for knife blades: Good, Better and Best. Each type of steel has unique properties that make it more suitable to specific designs and applications. And of course, the choice of steel will impact the knife’s price.
Good Blade Steel
Knives utilizing “Good” steel blades should be considered entry-level, and tend to be made from rust-resistant (not rust-free — see above) stainless steel. Typically manufactured in Asia, these knives offer a fairly good economic value. These blades are usually ‘softer’ and therefore require more frequent sharpening to keep the edge performing well. But, because they are in fact ‘softer,’ re-sharpening is fairly easy. Some of the more popular stainless steel blade materials in this class are 420, 440A and 7Cr13MoV.
420 stainless steel has a little less carbon than 440A. Many knife makers use 420 because it’s inexpensive and it resists corrosion fairly well. 420 steel sharpens easily and is found in both knives and tools.