Boring Basics

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The word boring has a lot of different meanings. In machine shop talk the word Boring means, “To perforate or penetrate, as a solid body, by turning an auger, gimlet, drill, or other instrument; to make a round hole in or through; to pierce; as, to bore a plank.” This is stated from Webster’s dictionary of the official meaning.

So, machine tools are used to make this process happen. A Boring Mill is a tool that is used to make the hole larger in a work piece that already has one. It is normally done with a single point tool.
A work piece is held still on a table that is vertical but can be adjusted for a horizontal boring mill. There is a head that is adjustable and vertical and attached to it is a spindle. This spindle holds the cutting tool and then feeds it horizontally into the work piece. This is called horizontal boring. A work piece is made to move or revolve on a table that is circular and horizontal as the tool is fed into it. This is called a vertical boring.
A machine that is called a universal horizontal boring machine has a spindle that is horizontal, which is mounted and supported in the front and moves up and down. The machine is configured in three ways: small and medium, medium and large, and large to extremely large items.
In the first configuration, the spindle diameters are up to 125 mm has a stationary front support, and the table can move in two directions mutually in a perpendicular direction. In the second configuration, the diameters can go up to 200 mm and still does the same perpendicular direction. In the last configuration, the spindles can go up to 320 mm and use no table but does use a front support or column that can either move in one or two directions.
How the machine gets all of its many uses is the spindle unit. A hollow spindle will carry a faceplate with a cutter (this is the main motion of the machine) and an inside boring spindle which drives in the axial direction (this is the feeder). There can be many combinations used at once depending on the ability of the boring machine. If the spindle unit has a separate drive for a faceplate for a radial slide and an inner spindle, is a great example.
Modern day trends in boring machines are: in moving parts reducing the friction, using numerical control, digital display, increasing resistance and rigidity to vibration, and control of the work process and remote observation in special and heavy duty boring machines.