A Guide to Knife Steel
Put simply steel is iron with carbon added to harden it. Often other alloys are added as well to give your knife different capabilities. Because the composition of steels differ, it’s important to pay attention to what kind of steel a knife is made of when considering a purchase. Depending on the tasks you want your knife to perform, different steels will need to be considered.
VG-1 Stainless Steel (V Gold 1 Steel): A high Carbon Molybdenum stainless steel that is manufactured by Takefu Special Steel Co. VG-1 has a Carbon content between 0.95-1.05, Chromium content between 13.0-15.0, Molybdenum content between 0.2-0.4 and contains less than 0.25 of Nickel (Ni). Molybdenum and Chromium form hard double carbide bonds during the forging process. This helps improve the abrasion and corrosion resistance of the steel. VG-1 is typically heat treated to reach hardness of 58-61 on the Rockwell Scale.
German 4116 Stainless Steel: A fine grained, stainless steel produced by Germany’s ThyssenKrupp. Often used for medical devices and food processing, the steels Carbon and Chromium content give it a great degree of corrosion resistance, as well as strength and edge retention. 4116 Stainless Steel has a Carbon Content between 0.42-0.55 and it’s Chromium content is between 13.8-15.
1055 Carbon Steel: 1055 Carbon Steel straddles the line between medium and high carbon steel with a carbon content between 0.50%-0.60% and with manganese between 0.60%-0.90% as the only other component. Typically reaching a hardness of 60-64 on the Rockwell Scale. 1055 is both holds a sharp edge and is incredibly tough because during the forging process it produces a near saturated lathe martensite with no excess carbides, avoiding the brittleness of higher carbon materials.
SK-5 High Carbon Steel: A Japanese produced high carbon steel, similar to the American 1080. SK-5 is a high carbon steel with carbon between 0.75-0.85 and 0.60-0.90 manganese. It typically approaches 65 on the Rockwell Scale after quenching, producing a mixture of carbon rich martensite with some small un-dissolved carbides. The excess carbide increases abrasion resistance and creates a good balance between toughness and edge retention.
AUS 8A Stainless Steel: A high carbon, low chromium steel producing a compromise between toughness and strength, edge holding, and resistance to corrosion. With a carbon content of 0.75, AUS 8A is a versatile steel, perfect for pocket knives.
1095 CroVan (Chrome Vanadium) Steel: 1095 steel with Chromium added for better hardening and Vanadium to aid in the bonding process. Carbon content is .95 with 0.5 Chromium and 0.2 Vanadium. A good steel for larger fixed blade knives.
1085 High Carbon Steel- Similar to 1095 but contains .85% carbon.
VG-10 (V Gold 10 Steel): A stainless steel produced by Takefu in Japan. It was originally designed for cutlery but has since seen extensively by Spyderco in their knives. It should not be confused with the similarly named VG-1 Steel. VG-10 has 1.0% Carbon, 15.0% Chromium, 1% Molybdenum, 0.2% Vanadium, and 1.5% Cobalt. VG-10 is fine-grained and takes an excellent edge.
440 Stainless Steel: a higher grade of cutlery steel, with more carbon, allowing for much better edge retention when properly heat-treated. Available in four grades: 440A, 440B, 440C, and the uncommon 440F (free machinable). 440C can reach up to 60 on the Rockwell Scale after heat treatment. Its Carbon composition ranges between 0.95-1.20% and is 16.0-18.0% Chromium. 440C’s sharpness and the ease with which its sharpened have made it a popular choice for knives and cutting instruments. 440A, having the least amount of carbon in it, is the most stain-resistant but is generally considered less desirable in non-marine blades as its not as strong.
420J2 Stainless Steel: A tough, inexpensive, corrosive resistant steel containing a medium amount of Carbon (0.15-0.36%). It can be hardened up to 56 on the Rockwell Scale and is used in many surgical
CPM-S30V Steel: CPM S30V is a martensitic stainless steel designed to offer the best combination of toughness, wear resistance and corrosion resistance. Its chemistry has been specially balanced to promote the formation of vanadium carbides which are harder and more effective than chromium carbides in providing wear resistance.
YK30 Steel- a carbon-tool steel that is combined with chromium to make a strong and resilient steel. Its resistant to wear and is high in hardness, measuring on the Rockwell scale at 57-59.