M6 thread in 42CrMo4: GREEN RING machine tap in practical testing
When machining components for front axles, process reliability, thread quality and tool life are crucial. This is exactly where the VÖLKEL GREEN RING machine tap HSSE, Form B, M6 with spiral point proved its strength in a practical test at an automotive supplier. The tool was used in the production of a component for front wheel axles made from alloy steel 42CrMo4. The result: the user was extremely satisfied with both the quality of the produced threads and the increased tool life of the new tools.
Why is 42CrMo4 so demanding for axle components?
42CrMo4 is an alloyed quenched and tempered steel with very good mechanical properties. In practice, it is often used wherever components have to withstand high loads. This also includes components in the automotive sector, for example in the area of front axles or rear axles.
In the application described, the tensile strength of the material was approximately 800 to 1,000 N/mm². This is relevant for thread machining because the material places significantly higher demands on the tool than many softer steels. During tapping, cutting material, chamfer form, chip evacuation and lubrication must work together precisely. Otherwise, problems such as increased tool wear, poor thread surfaces, irregular flanks or unstable tool life can quickly occur.
From VÖLKEL’s perspective, 42CrMo4 is therefore a good example of an application where not just any machine tap should be used. The key factor is a tool whose geometry matches the machining situation.
Which tap was used?
A VÖLKEL GREEN RING machine tap HSSE, Form B, in size M6 was used. The specific item is Art. No. 35338.
The GREEN RING line is designed for universal use in easy-to-machine and higher-strength materials. In this case, the combination of HSSE cutting material, Form B and spiral point was particularly important.
The spiral point supports controlled chip formation and chip evacuation to the front. This is especially important when producing through-hole threads. The chips are guided out of the hole instead of accumulating in the thread area. This makes the process more stable and reduces the risk of tool breakage or damaged threads.
Why is Form B with spiral point suitable for this application?
When manufacturing axle components, it is not only about cutting a single thread correctly. What matters is that the process works reliably and repeatedly. The tap must therefore cut cleanly over many machining operations and deliver consistent thread quality.
Form B with spiral point is particularly suitable for through-hole threads. The chamfer pushes the chips forward in the cutting direction and out of the workpiece. This relieves the thread area and ensures better process control.
This is especially important with a material such as 42CrMo4. The material has high strength and can lead to increased cutting pressure if the wrong tool is selected. A suitable cutting geometry helps to control this cutting pressure and produce the threads reliably.
In short: the GREEN RING machine tap used offers exactly the properties that were required in this application.
What role did lubrication play?
The tap was used in combination with an oil-water mixture as a lubricant. This is also an important factor. During tapping, lubrication directly influences friction, heat generation, chip formation and the surface quality of the thread.
A suitable oil-water mixture can stabilise the cutting process and help reduce the load on the tool’s cutting edges. Especially with higher-strength steels such as 42CrMo4, coordinated lubrication is crucial for achieving consistent results.
In the application, it became clear that tool, material, machine and lubricant were well matched. This combination was a key reason for the positive test result.
How was the thread produced?
The threads were produced on a flexible tapping machine with a radial arm. Such machines are often used when components need to be machined flexibly and secure tool guidance is important.
When machining axle components, this flexibility is a practical advantage. At the same time, the tapping process remains controllable. However, this requires the tool used to match the material and the machine.
The practical test at the automotive supplier shows: the VÖLKEL GREEN RING machine tap successfully proved itself in this setup.
What was the result of the test?
The result was clearly positive. The user was extremely satisfied with the quality of the produced threads. In addition, the new tools achieved an increase in tool life.
This is particularly relevant in practice. Longer tool life means fewer tool changes, fewer interruptions and greater process reliability. At the same time, thread quality remains at the required level.
Especially in the automotive sector, where components are often manufactured in recurring processes, this combination is crucial: stable thread quality, reliable tools and economical machining.
What does this application case show from VÖLKEL’s perspective?
This practical case clearly shows that, when tapping higher-strength steels, success is not determined by the material alone. What matters is the complete setup of tool, geometry, machine and lubrication.
The VÖLKEL GREEN RING machine tap HSSE, Form B, M6 with spiral point was the right choice for this application because it met the requirements of the 42CrMo4 material and the machining situation.
For users, this means: anyone producing threads in comparable materials or automotive applications should not consider tool selection in isolation. Especially with higher tensile strengths, it is worth examining the process as a whole.
Have your application checked now
Are you machining similar materials such as 42CrMo4 or looking for a process-reliable solution for tapping steel components? VÖLKEL’s application technicians will be happy to support you in selecting the right tool for your setup.
This is not only about choosing the right tap, but also about chamfer form, lubrication, machine, cutting data and the specific machining situation.
