To import files in Fusion 360 most users will use the "upload" workflow that is located in the data panel. The problem is that the Upload method assumes all unitless files (.stl or .obj) are made with centimeters. Instead, you should always use the Insert Mesh feature when you need to place a mesh file into your current design.[Read more...] about Why is my STL file 10X greater in Fusion 360?
[Read more...] about How to convert an STL (mesh) to a Solid in Fusion 360