When to Upgrade Your Taps

What are the important considerations when planning to upgrade the taps in your shop? Here’s the latest on tap evolution and the unique features being developed for high-precision and high-production thread-making.

Tapping is tough work to begin with, but without the right tool it often gets a lot tougher.

Poor chip evacuation can lead to scrapped parts and tap shrapnel everywhere, while the wrong coating or geometry means less-than-desirable tool life and productivity.

The good news is that cutting tool manufacturers have stepped things up by offering a range of high-quality tapping solutions. Among those solutions are roll and form taps, helical and straight-flute cut taps, taps with material-specific coatings and geometries, and taps that break the rules of traditional tapping.
 

The challenge is understanding which one is best for your material and machine tool, making sure you have the right toolholder and cutting fluid, and understanding how to troubleshoot a problem application.

Choosing from a Wide Array of Tapping Options

When it comes to tapping decisions, Lefty Zuo first asks his customers what kind of production quantities they are running and what kind of materials they use.

A regional product specialist for tooling systems and taps at Kennametal, Zuo notes that the needs of an automaker are far different than those of a job shop, for example, or the needs of a tool and die maker. While the former might use a highly specialized tap and base its success on how many seconds of cycle time it can shave off a given component, others might be looking for a general-purpose tap that provides good tool life in a wide range of materials. 

“For shops that thread Inconel one day and aluminum the next, and do so in relatively low quantities, we typically recommend a GOtap,” Zuo says.

“Spiral flute and spiral point geometries are available, as are a variety of coatings, making it possible to keep inventory levels low while still providing excellent tool life and fast, predictable threading,” he adds. “If the production needs are higher or the material is more demanding, one of our high-performance taps in either solid carbide or PM (powdered metal) might be more suitable. Whatever the case, it’s important for shops to recognize that there is a wide array of tooling options out there, and no one should settle for poor performance, regardless of the material.”

Tools for a Flexible Manufacturing Environment

Pete Gennuso, product engineering manager for OSG USA, agrees on the need to balance tool performance with tool crib inventory levels, which is why he recommends the company’s A Brand taps to many of his customers.

“It’s great in steel, stainless steel, cast iron, some of the nonferrous materials, and even hardened steel up to about 35 Rockwell,” he says. “So, it really covers the vast majority of applications that a job shop or another flexible manufacturing environment is going to encounter.”

As with Kennametal and most other cutting tool suppliers, OSG offers taps in both carbide and PM grades, with geometries and coatings that cover as broad a material range as possible without sacrificing tool life, hole quality or throughput. Many are also equipped with through-the-tool coolant, a no-brainer when you consider the need to keep holes well-lubricated and free of chips during tapping operations.

“You should do whatever’s possible to evacuate the chip,” Gennuso says. “That’s why we apply a variable helix to the flute. With a higher helix angle right at the chamfer, where all the cutting takes place, this increases the sharpness of the cutting edge and also keeps the chip nice and compact. And then toward the flute exit, we have a lower helix angle that helps pull the chip away from the part, eliminating the bird nests that so often occur during tapping.”

Read more: “When to Upgrade Your End Mills”

Which factors matter most to you when selecting taps? How do you determine the best ones for your shop’s needs?