How CAD files are exported to STL is an important process for accurate building of. parts. The step by step process for converting CAD files to STL was taken straight. from the mentioned companies websites. Definition. STL is the standard file type used by most or all rapid prototyping systems. A STL. is a triangulated representation of a 3D CAD model (figure 1). The triangulation of. a surface will cause faceting of the 3D model. The parameters used for outputting. a STL will affect how much faceting occurs (figure 2 and 3).
They used iron to replace bronze in implements and weapons. This shift occurred because iron, when alloyed with a bit of carbon, is harder, more durable, and holds a sharper edge than bronze. For over three thousand years, until replaced by steel after CE 1870, iron formed the material basis of human civilization in Europe, Asia, and Africa.. Source.
New steel: The Bessemer converter. The earliest evidence of steel production is from sub-Saharan Africa in the first millennium BC. The Haya people, from an area now in north western Tanzania, developed a technology for producing high-grade carbon steel that was in use until the 1950s.