VÖLKEL BLACK RING machine taps in the endurance test for cylinder block machining
When machining cylinder blocks, process reliability, thread quality and tool life are crucial. This is exactly where the VÖLKEL BLACK RING machine tap HSS-E, Form C, M8 proved its strength in a practical test at an automotive manufacturer. The tool was used in the production line for passenger car cylinder blocks made of grey cast iron GG25.
The result: With a single VÖLKEL BLACK RING machine tap, more than 6,000 threads were produced in consistently high quality. This meant that the VÖLKEL BLACK RING machine tap met the requirements defined by the user for approval in the manufacturing process.
Why is GG25 relevant for cylinder blocks?
Grey cast iron GG25 is frequently used in mechanical engineering and vehicle manufacturing wherever components have to meet high requirements for dimensional stability, compressive strength and vibration damping. A typical example of this is the cylinder block in a passenger car engine.
For thread machining, this means: the tool has to cut reliably, thread quality must remain consistent and the process must not be interrupted unnecessarily. This is particularly important for cylinder blocks because machining a finished component can take several hours. In such manufacturing processes, a great deal of time, energy and material has already been invested in the component before individual threading operations are completed.
A defective thread can therefore cause significantly more than just a tool change. In the worst case, it can result in rework, machine downtime or scrap on a component that has already undergone extensive machining.
Which tap was used?
A VÖLKEL BLACK RING machine tap HSS-E, Form C, in size M8 was used. The specific article is item no. 35142.
The BLACK RING line is designed for short-chipping materials such as grey cast iron, brass and bronze. In this case, the combination of HSS-E cutting material, Form C and nitrided surface was particularly decisive.
Nitriding gives the tap a harder surface. This can reduce wear and support a longer tool life. Especially in fully automated production, this is an important factor because tool changes should be as infrequent and predictable as possible.
Why is Form C suitable for this application?
The tool used was a Form C machine tap. This chamfer form is often used for short-chipping materials and is particularly suitable when stable thread machining with reliable chip formation is required.
Grey cast iron GG25 generally produces short chips. This makes machining it significantly different from tough, long-chipping steels. The key factor here is not only chip evacuation, but above all a robust cutting geometry that works cleanly and consistently over many machining operations.
In cylinder block production, the tap has to deliver this performance repeatedly. It is not about a single thread, but about a large number of threads under series production conditions.
In short: the BLACK RING machine tap used provides exactly the properties that were required in this application.
What role did the machining situation play?
The practical test took place in a fully automated production line on a multi-spindle machine. Machining was carried out horizontally, using emulsion as the lubricant.
The cutting speed was 8 m/min, with a spindle speed of 300 RPM. This meant that the tool was used under real conditions, as found in series production at an automotive manufacturer.
Automated machining in particular places high demands on the tool. The process is machine-controlled, repeatable and designed for efficiency. The tool therefore has to function reliably without constant manual monitoring. If a tap does not operate stably in such a process, downtime or quality issues can quickly occur.
The application showed that the tool, material, cutting data, lubrication and machine were well matched to each other. This combination was a key reason for the positive test result.
How was the thread produced?
The M8 threads were produced in a passenger car cylinder block made of grey cast iron GG25. Machining was carried out horizontally on a multi-spindle machine.
Such machines are used in series production when several machining steps have to be carried out efficiently and reproducibly. For thread cutting, this means: the tap has to work precisely and must not disrupt the automated process through premature wear or unstable results.
This process reliability is particularly important for cylinder blocks. The components are complex, machining is time-consuming and the requirements for dimensional accuracy and functional reliability are high. A threading tool must not only cut here, but also remain a permanently reliable part of the overall process.
The practical test at the automotive manufacturer shows: the VÖLKEL BLACK RING machine tap was able to prove itself successfully in this setup.
What was the result of the test?
The result was clearly positive. With a single VÖLKEL BLACK RING M8 machine tap, more than 6,000 threads were produced in consistently high quality.
This meant that the tool fulfilled the requirements defined by the user for approval in the manufacturing process. What matters here is not only the sheer number of threads produced. The decisive factor is that quality remained stable throughout the test period.
In practice, this means: fewer tool changes, fewer interruptions and greater process reliability. Especially in automated automotive production, this combination is crucial. A tool has to work economically while reliably delivering the required thread quality.
What does this application case show from VÖLKEL’s perspective?
This practical case shows very clearly: when cutting threads in grey cast iron, success is not determined by the material alone. What matters is the complete setup consisting of tool, geometry, surface treatment, machine, lubrication and cutting data.
The VÖLKEL BLACK RING machine tap HSS-E, Form C, M8 was the right choice for this application because it met the requirements of the GG25 material and the automated production situation.
For users, this means: anyone producing threads in grey cast iron components or comparable series applications should not consider tool selection in isolation. Especially in fully automated processes, it is worth evaluating tool life, process reliability and thread quality together.
Have your application checked now
Are you machining similar materials such as GG25 or looking for a process-reliable solution for thread cutting in grey cast iron components? The application engineers at VÖLKEL 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, surface treatment, lubrication, machine, cutting data and the specific machining situation.
Get in touch now and discuss your application.
