Machining

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 describes the apprenticeship program and other activities that toolmaker Komet of America is pursuing to bring new people into the metalworking industry as machinists. The company has met with some success working with the Tooling & Manufacturing Association and a local high school.

CBN grinding wheels offer the promise of higher productivity and longer wheel life, but they must be carefully maintained with dressing routines that differ from routines for standard wheels. This article details the techniques and tools needed to perform CBN wheel dressing effectively and economically.

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.

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.

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.

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.

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.

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

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.

The advent of CNCs made new threadmaking technologies practical. Among these technologies are rigid tapping and thread milling. This article describes the uses, techniques and benefits of these two threadmaking methods.

There are some tapping situations that call for a rigid tapholder and some that call for a length-compensating holder. Often the choice depends on the capabilities of the machine and the CNC driving the tap. This article discusses why a machinist might choose one type of tapholder or the other.