Drilling & Boring

The CNCs on many lathes don't have drill-pecking cycles.

A detailed description of a combination drill that machines six different nhole diameters. Used on a dedicated drilling machine that drills cast iron ncylinder heads, it was developed over a number of years.

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.

Small-diameter drills designed for drilling circuit boards can be used as a low-cost alternative for producing holes in other materials as well. Their fragility is the only drawback.

Spot drilling is a time-consuming process, but sometimes it is necessary to prevent drill walk. This article describes the reasons for spot drilling and the economic impact of adding the operation to a job. It also explains why a spot drill is a better choice for the operation than a center drill.

Routing coolant out through the tip of the tool can provide greater control of temperatures and chips. This article describes the benefits of through-coolant tools and describes the methods of retrofitting machines to accept through-coolant tools.

The author explains how high-pressure, high-volume coolant can provide better control of chips and temperature during drilling operations. He also describes the tools, equipment and shop procedures that can ensure top performance from a high-pressure coolant system.

Indexable-drill performance depends on insert selection, toolholding, coolant, and hole-entry conditions. This guide covers the setup details that most affect results.

Several factors influence the effectiveness of a drilling operation. This article looks at a number of them, including coolant delivery, speeds and feeds, and tool selection.

Drilling with a single- or double-tube system might be the most efficient way to drill deep holes in some applications. This article, which describes the tools and the process, says tubular drilling can pay for itself in higher productivity, thriftier manufacturing and tighter tolerances.

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 makes the case that a core drill is the best tool for opening existing holes. Being designed for the operation, the two-flute indexable drill can produce more accurate holes with less tool wear and breakage than alternatives such as boring bars, drills or endmills.