opener/wire stripper combination tool designed towards prying. Design and materials Rivets and flanged bushings made from brass hold all machined steel parts and other tools, separators and the scales together. The rivets are made by cutting and pointing appropriately sized bars of solid brass. The separators between the tools have been made from aluminium alloy since 1951. This makes the knives lighter. Previously these separating layers were made of nickel-silver. The martensitic stainless steel alloy used for the cutting blades is optimized for high toughness and corrosion resistance and has a composition of 15% chromium, 0.60% silicon, 0.52% carbon, 0.50% molybdenum, and 0.45% manganese and is designated X55CrMo14 or DIN 1.4110 according to Victorinox. After a hardening process at 1040 °C and annealing at 160 °C the blades achieve an average hardness of 56 HRC. This steel hardness is suitable for practical use and easy resharpening, but less than achieved in stainless steel alloys used for blades optimized for high wear resistance. According to Victorinox the martensitic stainless steel alloy used for the other parts is X39Cr13 (aka DIN 1.4031, AISI/ASTM 420) and for the springs X20Cr13 (aka DIN 1.4021, but still within AISI/ASTM 420). The steel used for the wood saws, scissors and nail files has a steel hardness of HRC 53, the screwdrivers, tin openers and awls have a hardness of HRC 52, and the corkscrew and springs have a hardness of HRC 49. The metal saws and files, in addition to the special case hardening, are also subjected to a hard chromium plating process so that iron and steel can also be filed and cut. Although red Cellulose Acetate Butyrate (CAB) (generally known trade names are Cellidor, Tenite and Tenex) scaled Swiss Army knives are most common, there are many colors and alternative materials like more resilient nylon and aluminum for the scales available. Many textures, colors and shapes now appear in the Swiss Army Knife. Since 2006 the scales on some knife models can have textured rubber non-slip inlays incorporated, intended for sufficient grip with moist or wet hands. The rubber also provides some impact protection for such edged scales. Modifications have been made, including professionally produced custom models combining novel materials, colors, finishes and occasionally new tools such as firesteels or tool 'blades' mounting replaceable surgical scalpel blades to replacement of standard scales (handles) with new versions in natural materials such as buffalo horn. In