Vertical boring is a machining process whereby a part to be machined is clamped to a bed and a machining tool is rotated to produce some cylindrical, internal feature in the work piece. The cylindrical surface to be produced is oriented in the vertical direction and the tool is typically fed down into the work piece.
Many vertical boring operations can be performed by a conventional mill and boring attachment, so in general vertical boring machines are used to machine large castings and blocks of metal too heavy for a regular mill.
One of the main advantages of carrying out the boring operation in the vertical position is the ease of clearing cuttings from around the cutting tool. Another key advantage is that the need for a large amount of power to rotate a very large block of steel and the associated dangers are avoided.