Extrema Ratio Extrema Ratio manufacturing and selling high performance combat knives since 1997 enjoying a reputation for excellence that is unsurpassed in the military and tactical knife industry. Extrema Ratio serves military and law enforcement communities as well as commercial markets and the knives are well known and sought after all over the globe.The company prides itself in design, material and quality to deliver a high end product that meets the most severe mil-standards.The production based on modern cutting edge technology is combined with traditional craftsmanship and the result is the pinnacle of this synthesis. The Extrema Ratio design team uses the 3D system to design new models and create prototypes. Extrema Ratio knives represent a real, solid value for the money. All of the knives are made from N690 Cobalt Stainless Steel which is a steel from a small plant in Austria, often used in the manufacture of surgical instruments. This steel along with their tempering methods produce a steel of great strength, flexibility with the capability to take and retain a razor sharp edge. The handles provided on the fixed blade knives are made from a grip polymer called Forprene which provides a very sure and comfortable grip even when wet. The folding range of knives have a shell made from a super strong anticorodal alloy and the best materials are used throughout to ensure reliability and longevity.