Articles & Columns

While superabrasives in grinding wheels generally perform better than conventional abrasives, the grains also possess characteristics that can lead to unwanted chemical reactions during the wheel manufacturing process or premature pullout during use. This article discusses the ways a coating applied to the grains can reduce or prevent these undesirable side effects. .

A CNC tool grinder connected to an automated loading unit can be programmed to grind tools during a shop's off hours. This article discusses the planning and preparation that are necessary to set up an unattended run.

This article discusses the various sources of machining information available, and the body of knowledge on which each type of source bases its recommendations. Emerging sources that make use of such innovative media as the Internet also are discussed.

This report details the results of a test of graphite electrodes. The test compared the performance and machinability of three graphite grades, ranging from an inexpensive coarse grade to a relatively costly ultrafine grade.

HSK toolholders were designed with high-speed machining in mind. This article explains the features of the toolholder that make it perform well in modern machining centers at high spindle rpm. It also discusses the toolholder's handling and maintenance requirements.

A toolholder that uses metal's natural thermal expansion and contraction to hold tools does not suffer from many of the drawbacks of other toolholding mechanisms, according to this article. In addition to outlining the benefits of this "shrink-fit" toolholding system, the article also explains the technology and describes how shops have benefited from it.

Dual-spindle turning centers allow shops to combine several processes into one setup. This article describes a typical dual-spindle turning center's configuration and capabilities. A common scenario is given showing how such a machine might be used to reduce cycle times.

CNC bandsaws are designed to run for long periods unattended. This is only possible if the blades used are reliable and long lasting. According to this article, bimetal blades with ground teeth fit the bill. The article describes how these blades are made and what makes them different from conventional blades with milled teeth.

Stainless steel is one of the more difficult materials to cut. This article discusses the problems that can occur when turning various types of stainless steels, the reasons for these problems and ways to avoid them. Advice is given on diagnosing problems based on tool-wear patterns. The article also suggests ways to correct problems once they are discovered.

Machine tool builders and distributors are trying to distinguish themselves by selling customers complete turnkey packages that are ready to make good parts from the day they are installed. This article discribes the services being offered and the process that puts a turnkey system on a shop's floor.

There are many good reasons a shop might choose to purchase an abrasive waterjet machine. However, as this article explains, many factors must be considered to determine if the investment makes economic sense. The article discusses how and when a shop can adopt AWJ profitably and it explores the possibility of achieving the same results more cost effectively by subcontracting the work to an AWJ specialty house.

As the use of hard-to-machine work materials grows, the need for high-performance tool coatings increases. This article discusses developments in coatings that have increased their usability. Among the coatings discussed are medium-temperature CVD coatings and multilayer PVD coatings.

Cutting without metalworking fluid is looking increasingly attractive to U.S. shops hit with the high cost of fluid maintenance and disposal. This article discusses the benefits and drawbacks of dry machining and outlines the tools and equipment needed to machine successfully without the benefits of a coolant or lubricant.

There are several types of feed units for drilling and tapping on the market, varying in capability and the type of drive. This article discusses the difference between units and suggests questions users should ask themselves before selecting a unit. Factors to be considered include the volume of production, cost engineering and tool requirements.

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. The article describes the design of a typical core drill and explains how it is used.

Superabrasive bore finishing can achieve the same results as conventional honing quicker and at a lower cost. This article describes the types of superabrasive tools available and their uses. The article also explains how to set up and break in the tools.

Solid-carbide drills made with advanced submicrograin carbide are capable of producing holes that meet tight specifications without secondary operations. This article explains how these tools produce reamer-like finishes while offering extended tool life and shortened cycle times. An accompanying article discusses coatings for solid-carbide drills.

Modular fixturing offers a flexible and reusable alternative to dedicated fixtures. This article discusses the benefits of modular fixturing and the types of jobs for which a modular system makes economic sense. A description of typical modular fixturing components and how they are used is also provided.

When shops crank up the speed, they have to be prepared for the consequences, even if they’re milling "easy-to-machine" aluminum.

Researchers tried bathing inserts in liquid nitrogen to keep them cool while cutting hard-to-machine materials. This article reports the results of this experiment. It shows how the use of cryogenic coolant can keep temperatures down and prolong tool life while machining titanium aluminum vanadium and reaction-bonded silicon nitride.