Thread grinding plays a critical role in modern precision manufacturing, with applications ranging from automotive steering systems to medical implants. STUDER is addressing the growing demands for thread quality and accuracy through its high-precision universal cylindrical grinding machines and intuitive software.
Threads are among the most widely used components in modern engineering. Based on a helical design that converts rotational motion into linear force, the principle dates back thousands of years. Initially used in applications such as presses and water-lifting mechanisms, threads became fundamental to industrial manufacturing following their standardisation during the Industrial Revolution.
Today, threads are essential across several industries and applications, from conventional fasteners to ball screws used in electric power steering systems and threaded components in medical implants.
As the performance and quality requirements of these components increase, their manufacturing becomes more challenging. Achieving the required precision, surface quality and consistency calls for advanced grinding technologies and reliable machine capabilities.
With its universal cylindrical grinding machines and intuitive software, STUDER aims to simplify thread production while enabling manufacturers to achieve high-quality results efficiently, including for demanding industrial applications.
High-performance threads are usually produced after the workpiece has been hardened; at this stage, the workpiece often can no longer be turned or milled but can only be ground. In this process, a specially profiled grinding wheel transfers the negative image of the thread profile onto the workpiece under synchronized CNC control. This process places the highest demands on the grinding machine in terms of precision: Tolerances are in the range of a few micrometers, reliable reproducibility is of the utmost importance, heat buildup quickly leads to grinding burn, and even the slightest vibrations affect surface quality. All of these are grinding technology challenges with which STUDER is thoroughly familiar. The modern universal cylindrical grinding machines from the Swiss technology company enable high-precision thread grinding for industrial applications.
versal cylindrical grinding machine.
Thread Grinding on a Universal Cylindrical Grinding Machine Offers Advantages
“There are numerous advantages for customers in being able to perform grinding operations on a universal cylindrical grinding machine rather than having to rely on a specialized machine,” explains Daniel Huber, CTO of Fritz Studer AG. The long-established manufacturer began developing innovative software in conjunction with a controlled C-axis for this demanding manufacturing technology in the mid-1990s.
Today, all STUDER universal cylindrical grinding machines in the current portfolio are capable of thread grinding with the appropriate software option. This universal machine concept offers clear advantages. Cylindrical, profile, and thread grinding in a single setup eliminates setup errors and ensures higher positional accuracy. Those who previously operated specialized machines or outsourced parts are now consolidating operations onto a single machine, saving floor space and bringing value creation in-house. It is therefore no surprise that one in six STUDER machines delivered is equipped for thread grinding.
Whether ISO metric threads, fine threads, mounting threads on tool holders, tapered threads, or internal and external thread gauges: On all STUDER models, the C-axis and software-based profile correction allow for the production of the vast majority of standard industrial components. “And for workpieces with a large lead angle, such as multi-start ball screws, worms, or extruder shafts, we introduced the A-axis as a swiveling grinding spindle axis in 2013,” explains Huber. It is available on the S41 and S22—a revolutionary mechanical solution that did not previously exist for universal cylindrical grinding machines.
A-axis, WireDress®, and SmartJet™: Maximum Performance in Thread Grinding
Another groundbreaking STUDER technology for thread grinding is WireDress®. Based on the principle of electrical discharge machining, this dressing technology for external and internal grinding on the S41 and S22 enables contactless dressing and profiling of metal-bonded diamond and CBN grinding wheels directly in the machine at full operating speed. The grinding wheels conditioned in this way are extremely sharp, reduce the risk of grinding burn, and can grind threads directly from solid stock. The result is significant productivity gains compared to conventional dressing methods. The intelligent STUDER coolant nozzle system, SmartJet™, has also been specifically further developed for thread grinding and prevents grinding burn. With the most powerful thread grinding configuration in the STUDER portfolio, even the hardest materials with steep lead angles can be ground reliably, such as carbide threads for tool holders, high-precision ball-screw threads in drive technology, or robotic lead screws in high-volume production.
All customers benefit from a well-designed software ecosystem that enables even less experienced users to get off to a safe start in thread grinding and reduces errors. StuderThread first creates the dressing program for the grinding wheel. The library of all common ISO standard threads included in the software, along with the ability to graphically configure multi-start threads or roughing and finishing teeth on milling cutters, significantly reduces programming time. During the dressing process, ExactDress uses Acoustic touch sensor technology to verify whether the grinding wheel profile is fully conditioned. The dressing process is automatically repeated until the grinding wheel is optimally shaped across its entire profile. InOneThread then takes over for the grinding cycle. The smart software graphically visualizes the thread grinding process on the screen in advance and suggests optimal cut sequences. The entire operating process is designed to be intuitive, and should any questions arise, customers always have access to STUDER’s reliable customer care as well as training from competent experts.
Intuitive Software for Every Level of Experience
The software, developed by STUDER with extensive grinding expertise, is embedded in C.O.R.E., the modern and highly networked operating platform for machine tools from UNITED GRINDING, featuring a large touch panel directly on the machine. The control system, programming aids, and process monitoring are all bundled into a user-friendly interface. STUDER’s extensive experience in automation also benefits customers in thread grinding. For example, STUDER machines can be configured for high-volume production using gantry loader systems to create fully automated grinding cells that deliver thread components with consistently high quality in unmanned operation.
In the future, the requirements for tolerances, materials, and surface quality in thread grinding will continue to rise, driven by trends such as electromobility, humanoid robots, efficiency, and sustainability, Huber emphasizes. That is why STUDER is constantly developing and optimizing its hardware and software and working on the implementation of new technologies. For example, the analysis of sensor data can further improve process monitoring and detect anomalies at an early stage. “Thread grinding on universal machines was a pioneering achievement 30 years ago. Today, it is one of the most economically attractive options in precision manufacturing for our customers,” says Sandro Bottazzo, CEO of Fritz Studer AG. He is certain that threads will remain a backbone of the modern world in the future.
The Advantages: Thread Grinding with STUDER
- All modern universal cylindrical grinding machines from STUDER are equipped with the appropriate software modules for thread grinding
- The optional A-axis on the S41 and S22 enables the machining of complex thread types with larger lead angles, which previously required specialized machines
- STUDER technologies such as WireDress® and SmartJet™ ensure a cool cut, minimal grinding wheel wear, and high productivity even with difficult-to-machine materials such as tungsten carbide, ceramics, or high-alloy steels
- The intuitive software, featuring StuderThread and InOneThread, guides even less experienced operators reliably through the thread grinding process and reduces errors