Feature Article

The choice of tapping driver, the component between the spindle and the tap, can affect the quality and accuracy of the threads as well as the rate of wear on the tap and the machine tool. This article discusses how features such as length compensation and self-reversing protect against damage caused by machine and tool errors.

Roll-forming taps produce internal threads by displacing the metal under pressure rather than cutting it. This article explains how to perform the operation to achieve good quality threads. Formulas and charts help the user calculate the proper size hole and the size of tap to use for a desired thread.

Deep-hole tapping raises chip evacuation, lubrication, and torque risk. This guide covers practical depth limits, tap selection, and process controls for deeper threaded holes.

Managers at California's Dowty Aerospace take full advantage of computers to design parts, program machines and track jobs from beginning to end. This shop profile talks about how Dowty has combined this computer-based organization with cell-based manufacturing to maintain efficiencies and keep lines of communications clear.

A shop supervisor and education manager recount the evolution of a job that didn't proceed exactly as planned. Because the powder-metal part was harder and its as-pressed dimensions were not as accurate as originally expected, adjustments and improvisations were needed to produce the finished parts as quickly and as cheaply as quoted.

This article reviews the nomenclature that toolmakers use to identify inserts. Both ANSI and ISO codes are described character by character. A chart lists all of the possible choices for each position in the code and what each code letter or number signifies.

This article compares hard turning to grinding for finishing hardened steel parts and discusses which operation would be more appropriate for various situations. The article also looks at the machine tool, insert and cutting parameters required during hard turning.

Honing was originally a surface finishing operation that did not remove significant amounts of material. This article discusses brush honing, a process the authors say produces results similar to what honing was originally intended to produce. Proper boring is also discussed, because, according to the authors, a properly bored hole will not require further correction through modern aggressive stone honing techniques.

According to this article, the short-bar barfeeders that are on the market today are not plagued by the drawbacks that have become associated with barfeeding. The units load 5-foot bar stock into a lathe rather than the longer stock loaded by earlier units.

The efficiency of a die-sinker EDM operation can be enhanced by automating at least part of the work handling or tool handling. This article describes the automation that is available, from the simplest electrode grippers to fully automated toolchanging systems.

Copper can be difficult to EDM because its thermal conductivity changes electrode wear and process behavior. This guide covers the settings and strategy shops should review first.

Advancements in bandsawing are allowing shops to closely control the cost and precision of the operation. This article looks at such innovations as informational computer programs that provide advice on workpiece positioning and machine settings. Improvements in blade design and the applicability of these new blade geometries is also covered.