An asymmetric line boring bar

Published Date
April 09,2015 - 03:15:pm

Automaker BMW challenged the Kennametal Inc. to develop a tool that accentuates the advantages of reaming and line boring while virtually eliminating the disadvantages. Kennametal accepted the task and developed its asymmetric line boring bar, which has two guide pads positioned so they only contact the last journal. This enables the boring bar to be quickly fed in and out of the multijournal bore without touching the workpiece. This geometry allows the bar to be fed through the raw, or unfinished, bores on an eccentric path.

For more information about Kennametal Inc., Latrobe, Pa., call (800) 835-3668 or visit

This video report is a supplement to "Crank up the bore," a Look Ahead article in the May 2015 issue of Cutting Tool Engineering.

Related Glossary Terms

  • boring


    Enlarging a hole that already has been drilled or cored. Generally, it is an operation of truing the previously drilled hole with a single-point, lathe-type tool. Boring is essentially internal turning, in that usually a single-point cutting tool forms the internal shape. Some tools are available with two cutting edges to balance cutting forces.

  • boring bar

    boring bar

    Essentially a cantilever beam that holds one or more cutting tools in position during a boring operation. Can be held stationary and moved axially while the workpiece revolves around it, or revolved and moved axially while the workpiece is held stationary, or a combination of these actions. Installed on milling, drilling and boring machines, as well as lathes and machining centers.