Boring is an internal machining operation that widens a pre-drilled or cast hole to achieve a precise diameter and straightness. Unlike drilling, which creates a hole from solid stock, boring relies on a rigid boring bar holding a single-point insert. Machinists use this process to hit tight tolerances and correct holes that have wandered off center.
We need to drill this out to half an inch and then finish it with a boring pass to hit the exact dimension.
Boring bars are notorious for chatter if they stick out too far; always keep the overhang as short as possible.
Related terms
Single-point
To cut a thread on a lathe with a single-point tool over several passes, rather than with a die or tap.
Backbore
To enlarge the diameter of a hole from the blind side of a workpiece.
Turning tool
A single-point cutting instrument used on a lathe to shape the outside diameter of a spinning part.