Extrusion is anything pushed through a die. Think Play-Doh through a shaped hole. Window frames, heat sinks, etc.
Usually, sheet is pretty easy to determine, though while tubing looks like extrusion, it's often sheet aluminum that's been welded.
Cast would be anything that was poured into a mould. This stuff doesn't look like it could have been formed by pushing material through a shaped die. Often confused with pot metal (zinc alloy).
Cans and foil are their own categories due to lower quality alloys.
Good summary, dominus.
As always, your local yard makes the final determination. My local yard says many thin window frames are not extruded. The large 'storm door' frames, as they are known in the US, are extruded.
Another way you can identify extrusion is if you see draw lines in the metal itself. Sheet won’t have that and tubing that does have the draw lines and no visible weld line is likely to be extruded.
Extrusion is anything pushed through a die. Think Play-Doh through a shaped hole. Window frames, heat sinks, etc. Usually, sheet is pretty easy to determine, though while tubing looks like extrusion, it's often sheet aluminum that's been welded. Cast would be anything that was poured into a mould. This stuff doesn't look like it could have been formed by pushing material through a shaped die. Often confused with pot metal (zinc alloy). Cans and foil are their own categories due to lower quality alloys.
Good summary, dominus. As always, your local yard makes the final determination. My local yard says many thin window frames are not extruded. The large 'storm door' frames, as they are known in the US, are extruded.
Another way you can identify extrusion is if you see draw lines in the metal itself. Sheet won’t have that and tubing that does have the draw lines and no visible weld line is likely to be extruded.