We insist all of our knives deliver extraordinary performance for their asking price. In other words, “they must deliver their money’s worth”.
In order to achieve this goal, we are vitally interested in all the elements that are critical to performance.
When it comes to the blade, these include profile, thickness, blade geometry, edge geometry, steel and heat treatment. Every one of these factors is studied in great detail to arrive at the optimum combination for a specific use. If the knife is a folder, we concentrate on the locking mechanism to ensure the strongest, safest construction. For handles, we strive to develop the perfect mix of materials and ergonomics to offer the most comfortable secure grip available. Above all, we TEST what we make! Rigorous testing is the only way to ensure we get the level of performance we demand.

Steel & Heat Treatment

Carbon V®

Some of our Cold Steel knives are made from Carbon V¨, a high carbon, low alloy cutlery grade steel. This steel is superior in performance to most other steels due to its chemistry and also because of the close controls that we maintain at every stage of the manufacturing process. These controls begin at the steel mill where Cold Steel specifies the desired microstructure of the steel. Once smelted, each steel shipment is microscopically checked for structural quality, cleanliness and chemical content by an independent metallurgist not in the mill’s employ. The blades are then blanked parallel to the rolling direction of the steel plate to optimize grain flow along the length of the blade. The final step is a precise heat treatment sequence that was developed by Cold Steel specifically for this custom steel. This heat treatment process is one of our most highly guarded trade secrets. It was arrived at over several years by using an exhaustive series of practical and metallurgical tests and observations.
Overall, we believe that attention to detail in every phase of the manufacturing process is the primary reason for the superiority of our blades.

San Mai III®

San Mai means “three layers”. It is the term given to the traditional laminated blades used by the Japanese for swords and daggers. Laminated construction is important because it allows different grades of steel to be combined in a single blade. A simple way to think of this type of 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 an entire blade was made “tough” the edge would not be hard enough to offer superior edge holding. San Mai III® provides a superior 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. This laminate is 25% stronger than the incredibly tough AUS8A stainless.

AUS Stainless
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, at Cold Steel® we 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.
AUS 6A is a medium to high carbon stainless which is tougher than ATS-34, 440C, ATS-55, etc., but still holds a good edge. This means it is particularly well suited for heavier, longer blades that are subjected to a lot of stress while chopping and hacking.
Like our other stainless steels, AUS 10A is a high carbon variety. It is equal in strength and toughness to AUS 8A but has the extraordinary advantage of an additional 20% in edge holding ability. This gives it a wide performance advantage over other steels like ATS-34, ATS-55 and 440V. The only knives Cold Steel® is currently manufacturing in AUS 10A Stainless steel are the Triple Action™ Folding Knives.

440A Sub Zero quench
Cold Steel® has always sub zero quenched the blades that we have manufactured in Japan, and we are now adding this often omitted, yet crucial, process to the heat treating sequence of the new blades we are making in Taiwan.
Typically, stainless steel blades suffer from retained austenite after they have been heated to critical temperature and then air or gas cooled. The big drawback of this procedure is that it doesn’t get the blades cold enough to assure complete transformation from an austenite to martensite grain structure. Only by freezing-sub zero quenching-stainless blades to 120 degrees below Zero (Fahrenheit), will the austenite be completely transformed to martensite. This, in turn, assures the blade will be as hard, strong, and wear resistant as it can possibly be.