For expanding, a larger expanding mandrel is pressed into the smaller center bore of the billet, whereat the displaced material of the expanded bore results in a lengthening of the billet and thus improves the yield (instead of chips when boring out the final billet diameter).

In an outline, making visible the collapsed task s that are immediately subordinate to summary task [D00647] MSP98

A technique for creating teaching opportunities based on a child’s interest. The adult restates what the child has said and adds one or two additional words. An expansion may include particular forms intended to teach language as stated in a child’s objective.

increasing in area or volume or bulk or range; "an expanding universe"; "an expanding economy"

That expands, or may be expanded; extending; spreading; enlarging.