Steel components in the planes are nearly always made from O1 grade tool steel; in the case of blades, the steel is hardened, but in most other cases it is not. I use O1 for a number of reasons, both structural and aesthetic. It is an extremely stable metal, and does not tend to distort from the stresses of construction to the degree that mild steel does. In addition, tool steel is quite easy to lap and smooth with abrasives, and can be taken to a wide range of surface finishes, from matte to mirror-polished. For some components and projects I work with 410 grade stainless steel, and commercial bronze for their aesthetic and structural qualities.
Infill materials are by far the most difficult, and the most expensive, parts of the plane to acquire. Over the years I have developed relationships with a number of sources for very high quality woods that are suitably dry and stable for planemaking. At any given moment, there are any number of options for infill material across the spectrum of color, figure, and grain. I welcome you to refer to the plane galleries linked at the top of the page to see examples of many of the species I have available.
All tools are made in my New Palestine, Indiana, workshop. Metal components, with the exception of certain screws, are always constructed from flat stock. Acme-threaded lever caps are single-point threaded and caps freehand turned. Sidewalls, soles, and front plates (where they exist) are always joined with a peined double-dovetail joint for a rigid structure that will outlast all of our children.