Articles

Grinding is a thermally dominated process, meaning a high percentage of process heat initially enters the part before coolant quenches it. Unless the coolant is applied at the correct flow rate and pressure, and the proper input conditions are selected, this process can lead to undesirable rehardening burn, thermal softening and tensile residual stresses.

Spindle bolts are made from difficult-to-machine, high-strength superalloys. They have very tight dimensional tolerances, which makes thread cutting a challenge. As a result of facing several thread-cutting problems during process development, we have learned important lessons at Mitsubishi.

If you've ever watched a bar of red-hot metal emerge from the furnace at a rolling mill, you might wonder how that scaly chunk of material became the smooth, shiny and accurate length of steel you just loaded into a lathe's bar feeder. Machinists know it as cold-finished bar stock. It got that way thanks to a process known as bar peeling.

The primary application for ultraprecision machining is optical-grade surfaces for injection molds, which are used to make contact lenses, LEDs for TVs and head-up displays in military aircraft and luxury cars.

Machining manifolds generates numerous burrs, and removing them is no simple task. Basin Precision Machining attempted a variety of deburring methods, including waterjet, kinetic energy and the thermal energy method (TEM).

In the August 2017 issue of Cutting Tool Engineering, Ask the Grinding Doc Columnist Jeffrey Badger, Ph.D., fields questions about spotting wheel loading, white sticking for hardened steel loading, and what causes barber pole marks during cylindrical-traverse grinding.

In the August 2017 issue of Cutting Tool Engineering, Shop Operations Columnist Tom Lipton challenges readers to take a good look at the venerable 4-jaw independent lathe chuck. "Many machinists may have never used one. Hopefully, my call to arms will change that, and a whole new world of workholding will open up to them."

A milestone in the 3D printing revolution is the appearance of CNC metalcutting machine tools incorporating additive-manufacturing capabilities. Manufacturers of the hybrid additive/subtractive systems tout their advantages over conventional machine tools, but the hybrids raise important issues that their builders and users must address.

Much of 2016 and 2017 has been a stressful roller coaster ride for our shop and me and my family as we have fought through a difficult economy—the worst in 30 years. Challenges remain, and business isn't completely wonderful again, but we have more optimism than a year ago, writes Keith Jennings, the Manager's Desk columnist for Cutting Tool Engineering magazine.

Since the time CTE Editor Alan Richter started covering manufacturing for CTE in 2000, industry professionals have frequently informed him that manufacturing jobs typically pay more than most other professions, such as sales and low-level, white-collar jobs. Furthermore, he was told, they provide a multiplier, or ripple, effect—in which one manufacturing job produces numerous other jobs. As he observes in his August 2017 Lead Angle column, Richter questions whether that's still the case.

Some machine tools are modified so much and so frequently it becomes a common practice. That's certainly the case with rotary transfer machines.

G2 Technologies has developed a customizable, automated 3D inspection system in response to a customer's need to inspect small electronic connectors. This niche is very specific, but impacts aerospace, automotive and other industries. The global market for the connectors industry is projected to reach $80.3 billion by 2022, according to G2.