A boring bar is a type of boring tool, generally with a round shank, although a square shank is sometimes used for larger workpieces. It is most commonly used for internal hole machining, reaming, and contouring. It is a tool with one or two cutting edges, specifically designed for roughing, semi-finishing, or finishing existing holes. Boring bars can be used on boring machines, lathes, or milling machines.
Due to different clamping methods, they come in various forms, including square shank, Morse taper shank, and 7:24 taper shank. A double-edged boring bar has two cutting teeth distributed on both sides of the center, cutting simultaneously. Because the radial forces generated during cutting are balanced, the cutting parameters can be increased, resulting in high production efficiency. Double-edged boring bars are classified into floating boring bars and fixed boring bars based on whether the insert floats on the boring bar. Floating boring bars are suitable for finishing holes. They are essentially equivalent to a reamer, capable of boring holes with high dimensional accuracy and smooth surfaces, but cannot correct straightness deviations in the hole. To increase the number of regrinding cycles, floating boring bars are often made with an adjustable structure.
To accommodate various hole diameters and depths and reduce the variety of boring tool specifications, boring bars and tool heads have been designed as modular components. Appropriate modules can be selected based on workpiece requirements to assemble various boring tools, thus simplifying tool design and manufacturing.
