The tools needed to build a World Heritage Knife varies depending on how involved you want to get in it's creation. At the simplest end, buying all the parts from a single World Heritage Knife manufacturer, all you will need is a screwdriver or small wrench to screw it together. If you want to mix parts from multiple manufacturers, you will probably also need a sheet metal nibbler or metal file to make adjustments on spacers. If you are having the parts custom made by a metal shop, you will need software to layout the design of the parts for you andallow you to make adjustments, and also a grinder to shape and sharpen the knife blades. If you want to care the knife out of sheet metal and use premade blade tools, sheetmetal nibblers, metal files, rulers, straight edges, triangles, etc... Want to make every part yourself? You should already be a professional at metalworking.