I'd also question what is meant by "high grade". Different alloys or material compositions have different characteristics for different needs. Add to that is the possibility that differing aspects of a frame might be served by differing materials. So a 4130 tubed frame might use a cast lug of a different steel and the braze ons or drop outs could be still another steel. With some AL frames there can be extruded tubes, die drawn tubes, machined bits and cast or forged parts. All needing their own spec.

When I've had these discussions with lay people (not that I'm a pro by any means) the unsaid assumptions/understandings are usually what's really being discussed, knowingly or not. Andy.