I posted this on another thread but I'll put it here also. I found this out when reading some posts that Blademaker, aka Gavin Hawk, made on this forum. He stated that the custom model MUDD was constructed of 6061 aluminum alloy, but said that Kershaw took it a step further and went with 7075 aluminum alloy, which is one of if not the toughest of the aluminum alloy's. So when you say the ZT0500 MUDD is one tough knife, you ain't kidding! Here is some info about these alloy's...
3003 is alloyed with 1.2% manganese to provide a tensile strength range of 17 to 30 KSI. Excellent workability, weldability, and corrosion resistance. Used for drawing, spinning, fuel tanks, sheet metal work and other applications where slightly higher strength than 1100 is required. Conforms to AMS QQ-A-250/2 and ASTM B209.
5052 is alloyed with 2.5% magnesium. Tensile strength range 31 to 44 KSI. Very good corrosion resistance, good workability, weldability and strength. Used for aircraft fuel tanks, storm shutters, refrigerator liners, utensils, electronic mounting plates and panels, fan blades, etc. Conforms to AMS QQ-A-250/8 and ASTM B209.
2024 is alloyed with 4.5% copper. Tensile strength range 30 to 63 KSI. Fair workability and corrosion resistance. Forming operations are limited. Used for high strength structural and aircraft applications. Also available as Alclad for improved corrosion resistance. 2024 conforms to AMS QQ-A-250/4 and ASTM B209.
6061 is alloyed with 1.0% magnesium and .6% silicon. Tensile strength range 20 to 42 KSI. Good formability, weldability and corrosion resistance. Used for engineering and structural applications, boats, furniture, transportation equipment, etc. Conforms to AMS QQ-A-250/11 and ASTM B209.
7075 is heavily alloyed with zinc with lesser amounts of magnesium, copper and chromium. One of the strongest of the aluminum alloys, its use parallels that of 2024 with 7075 selected when higher mechanical properties are desired. Forming operations are limited. Also available as Alclad for improved corrosion resistance. All 7075 flat products conform to ASTM B209; 7075 Bare conforms to AMS QQ-A-250/12, Alclad 7075, AMS QQ-A-250/13.