As long as the thread profile is 10 tpi or greater, you should be able to form it.” The limit is about 10 tpi, or 2.5 pitch in metric. “A fine pitch thread is easier to form because there is less material to displace. “There is also a limit on the pitch,” said Pat Nehls, product manager for Walter USA LLC, Waukesha, Wis., which offers the Protodyn CAP and Protodyn S Synchrospeed thread formers.

Larger tools produce more friction and require more machine horsepower. When form tapping titanium, a lot of that heat penetrates the tool and causes premature failure.įorm taps are typically less than 3⁄4 ', or an M20, in diameter. Because forming doesn’t create chips, the heat must go into the tap or the material. During a tapping operation, heat enters the workpiece, tap and chips, he explained. “In addition to its high tensile strength and low ductility, titanium has very low thermal conductivity, meaning that it doesn’t absorb heat very well,” Gennuso said. Brittle materials, such as cast iron, do not flow well and cannot be form tapped. Material with a tensile strength of 160,000 psi and a maximum hardness of 36 HRC is about the limit for form tapping, although form taps for some materials up to 40 HRC are available.Ī range of metals can be form threaded, including aluminum, stainless steel, carbon steel, titanium and nickel. He estimates the ratio of cut taps to form taps used is about 100:1.įorm tapping requires a workpiece material that can actually flow to create the thread profile.

But whether they call it form tapping, cold form tapping, thread forming, cold roll forming, roll forming, thread rolling, roll tapping or cold roll tapping, many metalworking professionals are unfamiliar with, according to Peter Gennuso, applications engineering supervisor for OSG Tap & Die Inc., Glendale Heights, Ill.Īl Zaitoon, marketing manager for YG-1 Tool Co., Vernon Hills, Ill., agreed that cut taps are more accepted and better understood. The process of displacing metal instead of cutting it is called many things. When the application is right, form tapping provides real production benefits.

Roll form tapping mic 6