A well-made knife is expected to function consistently without failing. However, making a knife that is not susceptible to failure can be difficult to do since a knife blade is sharpened to a fine edge that must not fracture or dull. To achieve this, it is important to select the proper knife material, as the incorrect metal and grade will ultimately end in premature failure and edge dulling. Not all metals are created equal for knives, so here are some examples of the best metals for making knives.
Tool steels are a very popular choice for making knives. Tool steels are, for the most part, carbon steels that have additional alloying elements that increase their mechanical properties. These alloying elements often increase the steel’s corrosion resistance as well, though not to the level of a stainless steel.
One tool steel grade that is used as a knife material is A2. While it cannot reach hardness as high as some other tool steels, it has excellent toughness. However, A2 could be subject to rust if care is not taken. D2 is another option that has better corrosion resistance and edge retention than A2; however, this is at the expense of toughness. M2 is a tool steel that is excellent at retaining a knife edge, but it can be too brittle for some applications.
Carbon steel grades with high amounts of carbon are desirable for knife making because they will give the blade the hardness and strength needed to hold up against impact and wear. However, proper heat treating must be performed on high carbon steels. If too rapid a quench is used, the knife will be too brittle and may fracture, while if the steel is allowed to normalize or anneal, it will be too soft and the knife will not hold a sharp edge very long.
Knives made from carbon steel can also be prone to rusting. This is due to carbon steels not containing many alloying elements that protect it from corrosion. Care must be taken to ensure that a carbon steel blade does not rust.
Common grades of carbon steel for knife making include C1045, C1075, and C1090.
Stainless steel is another type of knife-making metal. The added benefit of using stainless steel is addition of chromium and other alloying elements that increase corrosion resistance. Stainless steel knives are normally made out of ferritic or martensitic stainless steels. In order to make knives that have decent edge retention, the martensitic and ferritic grades of stainless steel need to have a high enough carbon levels to be able to reach high hardness. Grades such as 420 and 440 are frequently used for knife making.
Austenitic grades such as 316 may occasionally be used for knife making, however, austenitic grades are generally not able to be hardened enough to ensure a lasting edge. Low carbon versions of austenitic stainless steel, such as 304L, should be avoided when making knives unless corrosion resistance is the main concern and blade life is secondary.
There are also precipitation-hardening stainless steels that have excellent corrosion resistance and hardenability properties. These are typically used in applications where corrosion is a large concern. A commonly used precipitation-hardening stainless steel for blades is 17-7 PH. To achieve the maximum benefit of these alloys for making knives, one must know how to properly precipitation harden the metal.
Of course, there a wide variety of other metals and grades used for knife making, these are just a few of the common types.
Metal Supermarkets is the world’s largest small-quantity metal supplier with over 85 brick-and-mortar stores across the US, Canada, and United Kingdom. We are metal experts and have been providing quality customer service and products since 1985.
At Metal Supermarkets, we supply a wide range of metals for a variety of applications. Our stock includes: stainless steel, alloy steel, galvanized steel, tool steel, aluminum, brass, bronze and copper.
Visit one of our 80 locations in North America today.
Metal Supermarkets – Steel, Aluminum, Stainless, Hot-Rolled, Cold-Rolled, Alloy, Carbon, Galvanized, Brass, Bronze, Copper
Over 80 locations in North America offering instant access to a wide variety of metal types, shapes, sizes and grades.Find your closest store