Articles

Articles • August 1, 1995 • Dan Gajdosik

Threads Will Roll

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.

Articles • August 1, 1995 • Doug Moore

Driving the Tap

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.

Articles • August 1, 1995 • Al McBride

Thread Rolling on CNC?

Thread rolling produces OD threads by cold profiling the thread form onto the workpiece rather than cutting. According to this article, this yields significant benefits over using single-point tools to cut threads. The article also discusses the different types of thread-rolling units and their uses on modern machine tools.

Articles • June 1, 1995 • Alan Carius

PCBN Turns the Hard Stuff

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.

Articles • June 1, 1995 • Richard Thalmann

Cracking the Code

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.

Articles • June 1, 1995 • Kevin Ackman

Harder Than Anticipated

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.

Articles • April 1, 1995 • Jimmy Sherman

EDM Conquers Copper

Copper is difficult to EDM because of its high thermal conductivity. This article discusses the electrodes and machine settings to use for this demanding task.

Articles • April 1, 1995 • Anders Utterstrom

Optimal Automation

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.

Articles • April 1, 1995 • Dave Poling

Barfeeding Advances

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. This article describes how shops can use short-bar barfeeders to keep a lathe busy with a steady flow of work and still change from one bar diameter and part program to another easily and quickly.

Articles • April 1, 1995 • Guy Carmichael

Honing Comes Full Circle

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.

Articles • March 1, 1995 • Roy Leverenz

A Simple Groove

This article discusses the trend among insert makers to consolidate chipbreaker designs and carbide grades. The result is the three-chipbreaker/three-grade matrix many insert makers have adopted in some form. The evolution of the chip-forming groove is also traced, and an ANSI proposal for a grade identification system is described.

Articles • March 1, 1995 • Ann Marie Rooke

Saving Saw Bucks

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.