On 2017-01-23, Martin Eastburn wrote:
Think of working on nuts and bolts. One might have two or more sizes to
get a couch out of a wood crate or any thing you might come up with.

Consider the 'two drill chuck' drill - drill and screw or drill and
countersink....

Same sort of thing.

How about the combination drill and tap versions? Really
convenient for through holes with a tapping head in a drill press.

Enjoy,
DoN.

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