Articles & Columns

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.

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.

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.

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.

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.

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.

Software-based video tool inspection systems can read tool geometries much more precisely than other measurement systems. This article looks at the technology behind these systems and explains how this technology detects and measures tool edges and angles.

Tunable tools can be adjusted to dampen vibration. However, shops must have the right equipment to tune them quickly and precisely. This article describes an instrument that can provide the necessary feedback. A system that uses a mill's vibration frequency to sense problems with the tool is also described.

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.

The EPA's ban on ozone-depleting chemicals had an impact on the formulation of metalworking fluids containing 1,1,1 trichloroethane. This article looks at the reasons for the ban and the industry's efforts to find replacement substances for the banned chemicals.

Automatic recessing heads feed a cutter out at a right angle to the spindle's rotation axis as downward pressure is applied to the housing. This article looks at the advantages of using these units and reviews the different types of head available, including heads for special applications and multispindle automatics.

This is the first in a series of Articles on coolants. It provides a general review of the types of fluids available, their cooling and lubricating abilities and their ease of disposal. Criteria are offered for selecting the appropriate fluid for an operation.

When machinists plan a boring operation, they must rely on general turning data. Typically, this data is developed from OD turning operations, not boring operations. This article provides cutting data and recommendations specifically for boring that take into account such unique problems as boring bar deflection and chips trapped inside the bore.

This article looks at different machine tool components and their impact on the machine's ability to operate at high speeds and feeds. Components covered include motors, drives, bearings, spindle coolant mechanisms, toolholders and CNC.

Changes in milling practices have placed new demands on the cutting tool. This article discusses the features toolmakers have added to their milling insert geometries to control chips and cutting forces. The article also reviews the milling process and the forces that act on the insert.

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.

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.

Tapping holes 1 1/2 times the tap diameter or deeper requires greater care than other tap operations. This article discusses the chip evacuation problems that can make deep-hole tapping a challenge and the tap geometries and flute designs that can tap these holes successfully.

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.