Articles

Cermet inserts have evolved into cutting tools capable of finish-turning steel reliably at high speeds. This article traces the developments that have led to modern cermets and describes the properties that enhance the performance of these tools. The development of coatings for cermets is also covered.

New plunge-and-turn tools make it possible to perform several tasks, such as grooving, turning, back turning and face grooving, with the same tool. This article discusses the design and use of these tools as well as the types of cutoff tools currently on the market. Recommendations for tool selection, speeds and feeds are given for various work materials.

Indexable-insert drills offer several advantages for producing short holes. This article describes the drills' features, uses and benefits. Tips are provided to help select the optimal tool, insert and machine settings. A trouble-shooting chart is included.

High-performance aluminum-alloy workpieces are prone to residual stresses that can lead to part distortion. This article reviews the milling tools and practices that affect these stresses. Some tools and practices alleviate the stress, while others allow the machinist to mill the part without adding more stress.

Blades for contour bandsawing vary in their materials, their tooth set and selection, their width and the way they are welded. This article discusses how each of these variables contributes to the blades' ability to cut intricate shapes without seizing or wearing prematurely. Blade lubrication is also covered.

U.S. manufacturers are in a transition period, moving from inch to metric specifications. This article looks at the impact this change is having on the manufacturing and use of drills. The discussion also covers the advantages and disadvantages of going metric and the availability of metric drill sizes in the United States.

The development of the CVD thick-film diamond process has made it possible to produce tools that can machine abrasive work materials without losing their cutting edge. In this article, the technology for producing the diamond film and the brazing of these thick-film chips onto inserts is described.

To meet their customers' demands, mold and die shops are milling hardened steels at high speeds. This article discusses the use of coated carbide inserts to handle the heat generated by these operations. Specifically, the article talks about recently developed aluminum-titanium-nitride coatings, which reportedly are much more stable at elevated temperatures than other coatings.

Casting a pattern of light on a part and viewing that pattern at a different angle through a grating with the same pattern creates a moire pattern that can reveal small changes in the part's shape. This article tells how this phenomenon can be used by machine vision systems to measure part dimensions or pinpoint variations from a specified contour.

Programming a cut with an abrasive waterjet is complicated by the fact that the stream of water deflects as it passes through the workpiece. This article describes newer controller technology that can adjust the traverse speed to minimize deflection at corners and curves.

This article makes the argument that grinding is still a useful and necessary process despite the advancements that have made the turning of hardened workpieces possible. The article discusses the precision and finish possible with grinding, and it compares the cost of grinding to other machining processes.

While CNCs and part-handling equipment offer labor, time and money savings, they also require dramatic changes in the way a shop operates. This article looks at the investment in equipment, personnel and training that shops have to make over and above the cost of the automated machines themselves.