mm wrote:
(snip)

Two were a matching quarter inch drill and something I thought was a
drill, but is labeled Black & Decker Model 586 Tapgun.


It's a special drill for tapping (cutting threads). B&D used to market a
set of three drills for metal workers: holgun (drilling), tapgun
(tapping), and scrugun (driving the fastener). Looks like you got two of
the three.