Feature Article

Articles • October 1, 1995 • William Sluhan

Selecting Coolants: Why and How

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.

Articles • October 1, 1995 • Norm Semple

Beyond the Ban

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.

Articles • October 1, 1995 • Dr. William J. Westerman

Reassessing Recessing

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.

Articles • October 1, 1995 • Harvey Patterson

Strictly Boring

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.

Articles • September 1, 1995 • Joe Kraemer

Anatomy of a High-Performance Machine

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.

Articles • September 1, 1995 • Ken Booker

Milling Inserts Shape Up

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.

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 • Lee Carroll

Tapping the Deep Hole

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.

Articles • August 1, 1995 • Martin Eastman

It’s All Been Arranged

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.

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 • 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 • 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.