Nailset
Tool used for driving nail heads below the surface of a piece of wood From Wikipedia, the free encyclopedia
A nailset or nail punch is a hand tool used for driving the exposed head of a nail or pin below the surface of a piece of wood, such as when installing decorative moulding or face-fastening wood flooring.[1][2]

Though they vary in design, nailsets are typically made from a hard round or square steel rod which tapers at one end to a flat or slightly hollowed tip. The tip is placed against the head of the nail, while the other end of the nailset is struck with a hammer.[2] Nailsets come with different sized tips suited to different sized nail heads.
See also
References
Wikiwand - on
Seamless Wikipedia browsing. On steroids.