Articles & Columns

Former job shop finds success manufacturing custom gears with "impossible" lead times.

Understanding the fundamentals and possibilities of grinding, part 1.

Moldmakers represent a challenging niche market for the cutting tool industry.

Understanding parting-off operations

An examination of deburring and the cost of poor quality.

The use of compacted graphite iron is continuing to grow, particularly for automobile castings. The benefits of CG iron vs. gray cast iron are its ability to handle heat better and better machinability. The author gives an overview of the material's characteristics and discusses feed-and-speed considerations when machining CG iron.

A new drill point geometry developed by a tool and cutter grinder. The through-coolant drill is ground in such a way that a hollowed out chamber on the face of the tip retains coolant in the cutting zone while hydraulic forces that are created push fluid to the cutting edge.

Understanding parting-off operations.

Meadville, Pa., and the area surrounding the city are home to approximately 150 precision tooling and machine shops. The article explains why this city of 14,000 is such a hotbed of precision machining and entrepreneurship.

Examined are four recent developments in cutting tool coatings: "smooth" diamond coatings, which incorporates that are nanometer-sized; a process that deposits diamond on carbide substrates via a laser; highly lubricious coatings for dry-machining operations; and a patented system for "locking" conventional coatings together.

Tips for deep-hole tapping in titanium and other aerospace-grade materials. Advice is provided by NIST and the International Titanium Association.

The author gives an overview of the most common hardness testing methods: Rockwell, Brinell, Vickers and Knoop.

An expert on heat treating write about the advantages and disadvantages of available approaches and systems: stainless steel foil, atmospherically controlled furnaces, pressure-quench vacuum furnaces and two-zone vacuum furnaces. There's also a sidebar on cryogenic treatment of metals.

A new turning tool emits an electric signal when its insert reaches a predetermined wear point or breaks. Called Sensor Tool, sections of the coated insert are ablated by a laser, thereby creating an electronic circuit.

A look at the various types of CNC lathes available to shops contemplating stepping up from a manual machine. The pros and cons of the following lathes are discussed: combination, cutoff, slant-bed, twin-spindle and turn/mill. The author also touches on available options.

Part I: The author discusses how to maintain and repair machine tool spindles and what causes spindles to run out of round. Common sources of out-of-round spindles include loose bearings and improperly ground spacers. In-machine spindle repair is also discussed. Part II: There are three common ways to repair tapered toolholders: regrinding, replacing damaged material and chrome-plating. The author discusses each, along with its price, and gives advice about choosing an option.

Grinding burn is a general term used to describe various types of thermal damage that occur to the workpiece during grinding. The author supplies detailed information about each type of burn and offers advice for preventing it

Capability is determined by how well a process produces parts. Three measures of capability are important to a machinist: gage, machine and process. The author provides a detailed description of capability and suggests ways to quantify if a process is or isn't capable.

Cutting forces cause the boring bar to deflect, which can lead to vibration and damaged workpieces. The author gives an overview of available boring bars and offers guidelines for selecting one for a specific application.

DNC can mean either Direct Numeric Control or Distributed Numeric Control. Either way, a DNC links a shop's computers and machine tools and saves times. A DNC eliminates manual transcription of NC data, the downtime caused by shop personnel having to make programming entries and transporting part programs between engineering and their machines.