OSG Takes the Pain Out of Thread Milling with Innovation Trifecta

Finally, there’s the Diameter Correction Tool, or DCT, for thread mills that lets machinists determine how closely the threads being created conform to tolerances required for fit.

Fit is crucial in thread creation, since its purpose is enabling secure connection of two components: Think of a screw being twisted into a hole while assembling a complicated toy or piece of furniture, or a garden hose being attached to an outdoor spigot.

If the threads aren’t compatible, then you can’t finish the job.

“Previously, a customer would buy a thread mill, then drill a hole and cut it with the thread mill and use a general Go/No-Go gauge to determine where they were,” explains Applications Engineering Manager Jeff Stephens.

Depending on the results, they would alter the CNC machine’s settings until the threads were within tolerance.

“The issue is that takes a lot of time,” he says, and machinists were never sure how close their work on a particular piece was to either end of the tolerance spectrum.

OSG’s Diameter Correction Tool eliminates that ambiguity. Using either an analog sleeve or a digital readout device, machinists can see “whether they’re at 30 percent of tolerance, 50 percent of tolerance or 80 percent of tolerance,” Stephens explains.

With that knowledge, users “can set their tolerance on a higher level, and if the thread-mill wear is lower than that, they don’t have to adjust the machine’s settings to compensate as often,” he adds. “There’s a huge value of setup savings and cycle-time savings with this product line.”

Minimizing cycle time is vital for machine shops trying to meet customer deadlines while grappling with a shortage of workers that may reach 2.1 million by 2030 and simultaneously contending with surging inflation and supply-chain disruptions.

By enabling machinists to use thread milling without sacrificing valuable time or hurting productivity, OSG simplifies threading of large, expensive workpieces—especially those cast in alloys such as Inconel that are highly durable but consequently harder to cut.

Thread -milling is preferable for such products because there’s a lower risk of tool failure during the job.

That’s because thread mills are smaller than the holes being threaded and are essentially wheeled along their perimeter to create grooves, easily ejecting the small metal chips produced as a byproduct before they can clump together and impede the operation.

With tapping, the usual advantages of simplicity and ease that come from the tool and the hole being the same size are countered by the minimal channels for removing chips, which are forced out through grooves cut into the side of the tap.

If a tap breaks, removing it is difficult and time-consuming, according to Stephens. Sometimes, costly workpieces must be discarded altogether.

In those situations, a less arduous thread-milling technique can be a game-changer. If a thread-milling tool fails during a job, removing and replacing it is far simpler.

“Customers have been very impressed,” Stephens says. “We’re saving people over half of the cycle time, just with setups.”

OSG hasn’t stopped there. The toolmaker has also introduced new thread mills under its A Brand:

• The AT-1 enables threading with a single pass around a hole rather than requiring repeated turns.

• The AT-2, with an end-cutting edge for hard steels, eliminates the need for drilling a hole first. It shapes the hole and cuts the thread in one pass, helping to minimize the risk of tool breakage.
• The AT-2 R-Spec ThreadRacer adds continuous helical cutting ability to enable thread milling of nonferrous metals like aluminum at extremely high speeds.

“The tools themselves are game-changing,” Stephens notes. “Being able to go from four passes to just one pass is an incredible cycle-time savings. In high-production jobs, it’s a huge benefit.”