Types of Steel
VG-1 Stainless Steel
When considering a new material for a performance upgrade, Cold Steel tested seven different grades of steel including Shiro 2, V-SP-2, 10A, 440C, VG-10, ATS 34, and VG-1. Physical testing for sharpness, edge retention, point strength, shock, and ultimate blade strength showed that while many of the steels had increased performance in one or two testing categories, only one, VG-1, showed the greatest performance increases in the most critical categories. With an outstanding ability to retain an edge and proven strength in point and blade tests, VG-1 will provide Cold Steel customers with superior performance previously unavailable in a stainless steel blade.
San Mai III
A simple way to think of San Mai III blade construction is to imagine a sandwich: The meat center is hard, high carbon steel and the pieces of bread on either side are the lower-carbon, tough side panels. The edge of the blade should be hard to maximize edge holding ability, but if the entire blade was hard it could be damaged during the rigors of battle. For ultimate toughness the body of the blade must be able to withstand impact and lateral stresses. Toughness is generally associated with "softness" and "flexibility" in steel, so that, surprisingly, if a blade is made "tough" the edge won't be hard enough to offer superior edge holding. San Mai III blades provides a blade with hard (higher carbon) steel in the middle for a keen, long lasting edge and tougher (lower-carbon) steel along the sides for flexibility.
AUS 8A Stainless Steel
The words "stainless steel" are misleading, because, in fact, all steel will stain or show discoloration if left in adverse conditions for a sufficient time. Steel is made "stainless" by adding Chromium and reducing its Carbon content during the smelting process. There is a serious performance trade-off with stainless steel. As the Chromium increases and the Carbon decreases, the steel becomes more "stainless". But, it also becomes more and more difficult to sharpen, and the edge-holding potential is seriously impaired. This is usually why most stainless knives are rarely razor-sharp and quickly lose what little edge they have. In contrast, Cold Steel use AUS 8A Stainless, a high carbon, low chromium steel that has proven itself to be the ultimate compromise between toughness and strength, edge holding, and resistance to corrosion.
4116 Krupp Stainless Steel
4116 is a fine grained, stainless steel made by ThyssenKrupp in Germany and is used for hygienic applications (medical devices and the pharmaceutical industry) and food processing which make it a superb material for kitchen cutlery. The balance of carbon and chromium content give it a high degree of corrosion resistance and also impressive physical characteristics of strength and edge holding. Edge retention in actual cutting tests exceeded blades made of the 420 and 440 series of stainless steels. Other alloying elements contribute to grain refinement which increase blade strength and edge toughness and also allow for a finer, sharper edge.
1055 Carbon Steel
1055 steel is right on the border between a medium and a 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. The carbon content and lean alloy make this a shallow hardening steel with a quenched hardness between Rc 60-64 depending on exact carbon content. These combination of factors make this one of the toughest steels available because, when quenched, it produces a near saturated lathe martensite with no excess carbides, avoiding the brittleness of higher carbon materials. This steel is particularly suited to applications where strength and impact resistance is valued above all other considerations and will produce blades of almost legendary toughness.
SK5 High Carbon Steel
SK-5 is the Japanese equivalent of American 1080, a high carbon steel with carbon between 0.75%-0.85% and 0.60%-0.90% manganese. As quenched, it has a hardness near RC 65 and produces a mixture of carbon rich martensite with some small un-dissolved carbides. The excess carbide increases abrasion resistance and allows the steel to achieve an ideal balance of very good blade toughness with superior edge holding ability. Due to these characteristics, this grade of steel has been used traditionally for making a variety of hand tools, including chisels and woodcutting saws, and has stood the test of time and use over many years in many countries. Our working temper for these SK-5 steel knives are RC 57-58.
420J Stainless Steel
A common knife grade with low carbon, high chromium content steel which offers excellent bend toughness and wear ability. It offers excellent corrosion resistant characteristics as well.