Boring

The production of 'perfect holes' takes patience and careful planning.

Small bores present big challenges.

From the spindle to the cutting edge, advice on adjustable heads, boring bars and inserts.

Cutting forces cause the boring bar to deflect, which can lead to vibration and damaged workpieces. The author gives an overview of available boring bars and offers guidelines for selecting one for a specific application.

The author discusses the advantages and proper application of twin-cutter boring tools. They're recommended for rough-boring applications on castings, forgings and other jobs requiring a tool that can bore a cored hole. Details are provided on the three basic types of methods for rough boring with a twin cutter: balanced, stepped and full profile.

When machinists plan a boring operation, they must rely on general turning data. Typically, this data is developed from OD turning operations, not boring operations. This article provides cutting data and recommendations specifically for boring that take into account such unique problems as boring bar deflection and chips trapped inside the bore.

Although machinists are using cermet and ceramic cutting tools for an increasing number of applications, they have been slow to adopt them for boring. This is beginning to change, however. This article describes some of the ways a boring operation can benefit from the use of these tools.

This article relates how three shops used creative ideas to solve difficult boring problems. One shop built a custom tool to bore deep holes. Another used a combination of standard tools to bore an interrupted cut. And a third achieved tight tolerances with an assortment of plastic sleeves and plugs.

Ceramic and cermet cutting tools offer productivity-boosting benefits when the application is appropriate.