Chip-breaking operation when an existing hole diameter is increased by a rotary cutter. Beskrivning The process A shaft [1] is squeezed up through the hole whose diameter is to be increased. The shaft has a tool holder with a cutting insert [2] mounted which by rotation and axial movement cuts the hole wall. Depending on the detail design and size you can also perform the operation with a chuck instead of a shaft. Boring Process photos Process films Advantages and disadvantages In comparison with alternative methods Tight tolerances, good surface finish Handles very large diameters Suitable for drilling of several linearly spaced holes requiring high axial tolerance can often be performed on site with special tools slow process