Topic summary
Through hole

Extracted from the Wikipedia article Hole.
Blind and through
In engineering, machining, and tooling, a hole may be a blind hole or a through hole (also called a thru-hole or clearance hole). A blind hole is a hole that is reamed, drilled, or milled to a specified depth without breaking through to the other side of the workpiece. A through hole is a hole that is made to go completely through the material of an object. In other words, a through hole is a hole that goes all the way through something. Taps used for through holes are generally tapered since it will tap faster and the chips will be released when the tap exits the hole.