Cutting threads with an impact wrench: The VÖLKEL HexTap VX

Cutting threads with an impact wrench? The new VÖLKEL HexTap VX makes exactly that possible. Developed specifically for this application, this machine tap features an 11 mm hexagonal drive and can be connected directly to an impact wrench using a suitable adapter.

The HexTap VX is available in thread sizes from M8 to M30 and is aimed particularly at users in steel construction, mechanical engineering and industrial assembly. Thanks to its robust design, it is suitable for cutting threads in readily machinable materials with a tensile strength of up to 900 N/mm².

“When cutting threads with an impact wrench, precise axial alignment is especially important. The tap must not only be positioned exactly in line with the tap drill hole when starting, but must also remain aligned throughout the entire cutting process. Even slight tilting can place unnecessary stress on the tool and the thread.”

What sets the HexTap VX apart from conventional machine taps?

The key difference lies in the drive. Conventional machine taps usually have a cylindrical shank with a square drive and are operated using suitable tool holders. The HexTap VX, by contrast, features an 11 mm hexagonal drive specifically designed for use with impact wrenches. This allows users in steel construction or industrial assembly, for example, to work with machines that are often already part of their everyday equipment. Thread cutting can therefore be integrated into existing workflows without having to switch to a separate tapping machine.

The standardized hexagonal drive offers another practical advantage: All HexTap VX taps have the same drive size, regardless of thread size. When changing between different thread dimensions, users therefore do not need to change the tool holder each time. This simplifies handling, particularly in assembly work involving different thread sizes.

How is the HexTap VX connected to the impact wrench?

The impact wrench and the tap are connected using a suitable adapter. The adapter accommodates the 11 mm hexagonal drive of the HexTap VX and transfers the machine’s torque to the tool. Depending on the thread size, VÖLKEL recommends different impact wrench drive sizes, since larger thread diameters generally require higher torque for thread cutting.

The hexagonal drive size remains the same across the entire range. What matters is that the adapter used matches the impact wrench drive and is suitable for the particular application.

Which materials and applications is the HexTap VX suitable for?

The HexTap VX was developed for general use in readily machinable materials with a tensile strength of up to 900 N/mm². These include unalloyed and low-alloy steels in particular. Typical areas of application are steel construction, mechanical engineering and industrial assembly, where threads are cut directly into components or structural elements. One possible example is producing an M16 through-hole thread in a suitable steel component during assembly. The HexTap VX has a Form B spiral-point chamfer that pushes the chips forward in the cutting direction, allowing them to exit through the open hole. By contrast, this design is not the preferred choice for blind holes.

To withstand the mechanical and thermal stresses involved in thread cutting, VÖLKEL uses taps ground from solid HSSE material. This cobalt-alloyed high-speed steel offers high hot hardness and contributes to the tool’s wear resistance. In addition, the HexTap VX has a TiAlN (titanium aluminium nitride) coating. This hard coating protects the cutting edges against abrasive wear and offers high thermal resistance. This helps support a longer tool life and consistent cutting results, particularly in repetitive applications and with larger thread diameters. However, the material, tool and machining conditions must still be compatible.

What should you bear in mind when cutting threads with an impact wrench?

Although the HexTap VX was developed specifically for impact wrenches, the basic requirements for producing a clean thread still apply. A correctly sized tap drill hole is particularly important. If the hole is too small, the load on the tool increases significantly. If it is too large, the finished thread may have insufficient profile height. Equally important are maintaining precise axial alignment of the tap throughout the cutting process and using suitable lubrication to reduce friction and heat generation.

There is no universally applicable set of machine settings. Speed, torque limitation and use of the impact mechanism must be matched to the particular material, thread size, tap drill hole and overall machining situation. High available torque alone therefore does not guarantee a good thread. What matters is the interaction between the machine, tool and application.

Not sure whether the HexTap VX is suitable for your application or which settings make sense? Our application engineering team will be happy to help you select and coordinate the right tools. Simply contact us and we will be happy to assist you.

HexTap VX: Technical specifications at a glance