| 摘要 |
<p>For cutting a facing such a countersink or a spot facing a rotary cutter is provided with a body (2) having a central aperture (4) arranged to receive a drill (T) or other guide and at least one cutting insert (10) carried by the body rotates with the drill or guide to cut the facing. The insert has a forward cutting edge (16) which projects radially inwardly to form a step (18) projecting inwards relative to the main body of the insert behind the cutting edge region. The drill (T) has a radially recessed portion, such as the radial relief (R) or the flute of the drill, to accommodate said step of the cutting edge region. Such a cutter can be designed to operate at high metal removal rates and can be used with standard forms of drill and reamer.</p> |
