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OTEC’s New SF-HP Is Designed For Heavy and Large Workpieces

OTEC recently expanded its range of stream finishing machines with the addition of the SF-HP, which is designed specifically to accommodate heavier and larger workpieces for industries including aerospace, food, forming tools, machinery construction, energy, oil and gas. 

The SF-HP is the world’s first stream finishing machine for workpieces with a diameter and length up to 650 mm and weighing up to 200 kg. Due to the large number of axis settings for the process head and spindle, almost any movement of the workpiece through the process media is possible. This results in precise surface finishing in the shortest possible time, even for the smallest of workpieces. The stream finishing technology provides a green mechanical process without aggressive chemicals. The finishing process improves the tribological surface properties by reducing friction and abrasion.

Prior to the introduction of the SF-HP, OTEC’s SF series machines could only accommodate smaller workpieces up to 350 mm in diameter, 400 mm in length and up to a weight of 60 kg. The new machine also provides an ergonomic solution in the handling of these large and/or heavy workpieces. The customer only needs to place their workpiece into our machine loading area, which can be done with a trolley that is docked to the machine. The loading and unloading of the SF-HP is done with an integrated loading system which picks the work-piece from the loading area, loads it in the processing area and then brings it back again to the load-ing area. In both cases no manual loading of large and/or heavy workpieces is necessary. No robot programming knowledge is needed to program the integrated loading system. 

The SF-HP provides the customer with maximum flexibility for workpiece processing. It combines three different drive technologies into one system. With this one system you can either rotate your workpiece at different speeds in one direction, use the step function to place your workpiece at certain angles in the media, or use the pulse finishing technology. Thanks to a large number of axis settings and a flexible process head, you can program almost any workpiece movement through the process media, which guarantees the best possible finishing. 
If you’d like to learn more about the SF-HP, please send us a sample processing request.

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OTEC Präzisionsfinish GmbH recently collaborated with Airbus’ TED (Technologies et Energies de Demain) team for the Shell Eco-marathon, one of the most notable energy efficiency competitions in the world, where participants are challenged to design a vehicle that can travel further than any others on just one liter of fuel. The Airbus TED team turned to OTEC for targeted surface processing technology that produces a marked improvement in the tribological properties of drive components.

The partnership was sparked by the recommendation of a major automotive manufacturer involved in motorsports. OTEC Präzisionsfinish was brought on to  process a variety of components including mechanical precision polishing of gear wheels, crankshafts, camshafts and piston rings to guarantee the indispensably high-quality levels demanded in racing.

Alongside vehicle weight, aerodynamics and tyres, friction plays a decisive role in the drivetrain. The more precisely each relevant component is polished while preserving its geometry, the better its tribological properties – and the lower the friction. And the lower the friction, the further the vehicle can travel on that one liter of fuel.

Marc Denante, a member of the Airbus engine development team shared, “The surface finishing of piston rings and other parts in OTEC machines demonstrably reduces friction in the engine. This becomes visible through reduced fuel consumption while maintaining the same engine performance. After second place with 2.561 km/l consumption in 2019, the goal is now to become the world champion in 2021!”


OTEC Präzisionsfinish has a strong understanding of motorsports and the importance of surface finishing processes and their influence on a workpiece’s tribological properties. In engine, motor and drivetrain components, tribological surface properties are a critical factor in friction and wear behavior and have a huge impact on performance. Changing the surface topography and adapting the surface microstructure for optimal runin are crucial. OTEC’s stream finishing process achieves precisely that, increasing drivetrain efficiency in combustion engines and electric drives.

OTEC also has a long-standing track record in assisting Germany’s Halder Motorsport team. Michelle Halder made history in September 2020 when she became the first female winner of a TCR Europe series race. After a perfect start at the Sunday race in Zolder, Belgium, she left her rivals trailing, maintaining a breathtaking pace right to the finish. 

OTEC’s passion and experience led the AIRBUS TED team to choose two OTEC process technologies for their finishing needs.


The piston rings for this project were wet-polished in the OTEC CF-Series disc finishing machine, where workpieces are processed in an open container that has a disc-shaped floor with a rotary bearing. Components are added to the fixed container along with a suitable grinding or polishing granulate. When the disc turns, the contents are set in motion in a toroidal flow. Centrifuging the granulate and workpieces makes this process highly intensive. 


OTEC processed the large, complex components for this project such as camshafts,  in our SF-Series stream finishing machine. In this process, which was developed inhouse, the components are clamped in a holder and immersed in a rotating container filled with an abrasive or polishing medium. The workpiece itself is also rotated to produce an even finish. This helps achieve high-quality surfaces even on the most complex geometries, achieving roughness depths of up to Ra 0.01 µm.

To learn more about OTEC’s mass finishing solutions for the automotive industry, send us a sample processing request

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Extruders are widely used for a variety of conveyed goods in the food industry and the screws are usually ground and polished by hand, which is costly and time-consuming. Extruders move not only bulk goods but also viscous masses such as dough. A rough surface is prone to food residue and micro-organism deposits, which makes surface cleaning much harder. Additionally, sharp, unstable edges are problematic since they can repeatedly break off when under stress, leaving small fragments in the food. The only way to prevent this, and to guarantee uninterrupted production and food purity, is smooth, even surfaces in even the smallest angles, and rounded, stable edges. Typically, components used in the food industry are post processed in several steps, which can take several hours and is very costly. Since extruders can be heavy and unwieldy, the risk of injury from sharp edges is high.


The most efficient and cost-effective way to obtain evenly smoothed surfaces and rounded, stable edges is customized post processing using OTEC stream finishing technology: a mechanized, reliable, repeatable process for smoothing and edge rounding. Targeted, controlled processing ensures that the extruder screw can do its job unimpaired: no catching, no increased resistance and no deposit build-ups.


Schaaf Technologie GmbH manufactures screw extruders. Manually post processing the parts after turning and milling used to take the company around four hours. Recently Schaaf Technologie replaced all of this manual processing with OTEC’s efficient stream finishing process. 

According to Ron Hanke, Production Manager at Schaaf Technologie, “The OTEC stream finishing process means that we can process our screw surfaces automatically, evenly and consistently. The new process also improves tribological properties all-round, which in turn extends the service life of the parts by reducing friction. The process now takes just 30 minutes, and the time it takes for our employees to load the machine is minimal. We even obtain a better surface result than we did with manual finishing. The OTEC stream finishing process gives us a huge advantage in terms of both quality and time.”


OTEC’s stream finishing (SF) process, which was developed in-house, is ideal for particularly complex geometries. Components are clamped in a holder and lowered into a rotating container filled with an abrasive or polishing medium. The workpiece is also rotated to produce an even finish. This makes it feasible to achieve highly refined surfaces with roughness depths of up to Ra 0.01 µm even on the most complex geometries – all without manual strain or risk of injury. 

The enormous machining forces used in stream finishing can remove material faster and more precisely than any other type of surface processing. It is also easy to store and retrieve custom process programs, ensuring repeatability. 

OTEC’s latest innovation, the SF-HP, can even process large and heavy workpieces with a diameter and length of up to 650 mm and a maximum weight of up to 200 kg.


Work with us to identify exactly the right process for your components. Contact us today to request sample processing.

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Drag Finishing For The Tool Making Industry

In the drag finishing process, workpieces are clamped in specially designed holders. These holders are dragged in a circular motion through a process drum containing grinding or polishing granualate. This high-speed motion generates high contact pressure between the workpiece and the media, which quickly produces perfect results in the form of high-precision edge rounding, smoothing or a mirror-finish with results equivalent to those obtained by manual polishing.

One of the main applications for OTEC’s drag finishing machines is in the tool making industry. Some of the parts that can be processed using drag finishing include:

  • carbide cutters, thread-cutting dies, inserts and small broaches – processing these parts in a drag finishing or stream finishing machine reduces the risk of chipping. Precision rounding of the cutting edges and polishing the chip flutes increases tool life and improves cutting performance.
  • PVD and DLC coated workpieces – Stamping, forming and cutting tools are often coated with a carbide material in order to reduce wear. As a result, droplets can form on the surface of the tool. The drag finishing process selectively removes these droplets. Lubricant can be retained in the tiny holes and depressions left behind. This gives an improved film of lubricant on the surface of the tool, resulting in much less friction and reducing wear dramatically.
  • finishing of stamping and forming tools – the quality of stamping and forming tools can be improved considerably with the OTEC finishing process. Surface finishing lowers the coefficient of friction and thereby reduces wear at the surface of the tool. Polishing the forming surfaces can considerably increase the life of stamping and forming tools and improve tool performance. Smoothing the roughness peaks reduces the forces required and gives better flow characteristics during forming. In order to ensure that the quality of tools remains constant, regular repolishing is absolutely essential. Finishing in OTEC machines not only cuts down on expensive manual finishing work, but also delivers absolutely reliable and reproducible results.
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OTEC’s CF 50 Disc Finishing Machine’s New Design

OTEC’s CF 50 disc finishing machine now boasts a brand new compact design, with an optimized welded structure that guarantees reliable operation and a long service life. The updated design also features storage space for two compound containers and a waste water pumping station with a tray. The optimized spraying system with an additional rinsing nozzle enables process containers with the patented zero gap system to be filled quickly.

Another feature of the new design is a 7.5-inch color touch display for operating the machine that allows users to quickly and easily create, store and retrieve up to 5,000 programs. This makes operation extremely user-friendly. Thanks to the optional remote maintenance function, OTEC can carry out maintenance work on your machine without being onsite. It can also be set up for remote control if required, so you can be flexible in where you control the machine from. 

The CF 50 disc finishing machine is suitable for any rapid surface processing requirement involving larger fine blanked, turned, milled and punched parts as well as jewelry.

The OTEC CF Series disc finishing machine is the result of over 20 years of experience and pioneering innovation. Thanks to the optimal design of the containers and gap, our machine provides the ultimate in reliability and short process times.

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Stream Finishing For The Automotive Industry

In the automotive industry, the surface finish of individual components is crucial. So-called bulk goods are typically finished using disc finishing machines whereas sensitive parts that need to be finished to a greater degree of precision require the use of stream finishing or drag finishing machines. At OTEC, we offer a variety of finishing machines that meet the needs of the automotive manufacturing industry to ensure a perfect surface finish and increased service life of components.

OTEC’s stream finishing machines can be used to process cylindrical or near-cylindrical components – mainly the shell surface. With a wide choice of grinding and polishing media and a host of machine parameter settings, OTEC can provide the perfect process for almost any workpiece including gear wheels, crankshafts, camshafts, valves, spindle drives and other gear-type components. 

OTEC’s stream finishing process can help change the surface topography and adapt the surface microstructure of engine, motor and drivetrain component surfaces, contributing to

increased drivetrain efficiency in combustion engines and electric drives. The tribological properties of these engine, motor and drivetrain component surfaces are a critical factor in friction and wear behavior and have a huge impact on their performance. Achieving the perfect finish ensures minimal friction and wear. 

Some of the advantages of OTEC’s stream finishing machines include:

  • A reduced friction coefficient
  • An overall reduction in friction
  • Less wear
  • Increased internal compressive stress 
  • A more streamlined production chain since deburring and other techniques can often be replaced by stream finishing  

OTEC can develop a custom process designed specifically for your workpiece and application. Please send us a sample processing request if you would like to work with us. 

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OTEC’s Newest Stream Finishing Machine

OTEC is expanding its SF Series of stream finishing machines, with the addition of the SF-HP model, designed to accommodate larger and heavier workpieces. With its modern and compact design, the SF-HP was developed to round edges, polish, smooth and deburr large workpieces. This innovative machine can be used for applications across a variety of industries including aviation, machinery construction, forming tools, the energy, oil and gas industry, shipbuilding as well as the food industry.

Repeatable high-quality surfaces are guaranteed thanks to OTEC’s proven Streamfinish technology. Our unique, patented pulse finishing process is also integrated in the new SF-HP. Economical processing of large and heavy workpieces is now a reality. 

The new machine can process workpieces that are up to 650mm (25.5906 inches) in diameter and/or length and 200kg (440.925 lbs) in weight. Other features include a simple and intuitive user interface. Additionally, a variety of axis settings for the process head and spindle make almost any flow-through process media of the workpiece surface possible.

Some of the benefits of OTEC’s SF series stream finishing machines include: 

  • High efficiency and short processing times
  • A range of processing options depending on the requirements, including smoothing, high-gloss polishing, edge rounding and deburring.
  • User friendly operation through a multi-touch color display screen
  • Ergonomic machining of large and heavy workpieces through integrated automatic loading. 
  • Simple container changing enables multi step processes using different media. 
  • Improved tribological surface properties, which provide reduced friction and abrasion.
  • The highest surface qualities down to the smallest geometry. 

To see if OTEC’s new SF-HP stream finishing machine is right for you, please submit a sample processing request and we can develop a process specifically designed for your workpieces and applications. 

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Choosing The Right Media And Compounds For Disc Finishing

OTEC Präzisionsfinish GmbH recently hosted a webinar on how to select the best media and compounds for a disc finishing process. The webinar shared some of the benefits of choosing the optimal grinding chips and compounds for your process, including shorter processing times and obtaining the desired results more efficiently. 

The training also provided an overview of the different media that can be used with disc finishing machines, including plastic, ceramic and porcelain grinding chips. Additionally, during the webinar, best practices for choosing the ideal compounds for wet finishing processes were also discussed.

Possible applications for OTEC’s disc finishing machines include: 

  • In medical and pharmaceutical manufacturing, for surgical fasteners, bone screws, bone plates and milled parts, ear molds, dental implants and acrylic teeth.
  • For the automotive industry, in the manufacturing of pieces including gearbox and engine parts. 
  • In the jewelry and watchmaking industries,  for working parts of mechanical watches and polishing gemstones. 

To view this webinar on demand, please reach out to us via our inquiry form.

To see if OTEC can help implement or improve a disc finishing processing for you,  please submit a sample processing request.

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Stream Finishing For Knee Implants

According to WebMD, knee replacement surgery is one of the most common bone surgeries in the United States. As knee replacement surgeries become more common, there is more demand for the artificial joints used for these procedures. OTEC’s stream finishing machines are highly effective for deburring, rounding, smoothing and polishing axially-supported knee prostheses, a frequently-used type of knee implant.

Axially supported prostheses feature two components joined by a stabilizing hinge, with one of the components featuring a box-shaped configuration. Because of this box-shaped structure, finishing these parts can be challenging. Some of the advantages of utilizing OTEC’s stream finishing technology when working with knee implants include: 

  • Uniform surfaces
  • Consistent workpiece quality
  • Process reliability
  • No manual finishing
  • Option to process up to three knee joints in one pass
  • Quick process time 
  • No programming required

Using OTEC’s stream finishing machines, workpieces are clamped together and lowered into a rotating container filled with an abrasive or polishing medium. The workpiece rotates and is processed as the medium circulates around it. Our SF Series 3 Automation Stream Finishing machine can perform multiple processing steps very quickly in a single operation, which means a workpiece can be rapidly deburred, rounded, smoothed and polished in sequence, with no additional workload. 

Because of the unique box shape of stabilized knee implants, OTEC’s stream finishing machines offer two main advantages:  a contour-controlled motion sequence and an adjustable workpiece angle. These features make it possible to target the media flow at specific sections of a workpiece for particularly intensive processing. That translates to effective results in minimal time. Material abrasion can be controlled and it’s also possible to set precise roughness parameters based on the process: with initial work-piece values of Ra 0.8–1.2 µm you can achieve outstandingly smooth target values of up to Ra 0.01 µm.

When processing large volumes of workpieces, short loading and set-up times make operations much more efficient. OTEC’s SF Automation Series machines can be fitted with optional pulse finishing and work well in cyclic production lines. Depending on the requirements, the machines can either be set up for automatic loading or fitted with it as an integrated option. The machine design is modular and therefore easy to adjust to cycle time. Additionally, our SF Automation Series machines can be easily integrated as elements of any production line.

At OTEC, we can deliver the right machine for any surface finishing requirement, along with the ideal abrasive and a customized process. We can adapt and develop specific solutions based on your needs. We’re able to come up with a process based on your samples and ensure it’s reproducible and efficient, with professional documentation for all process technology parameters. 

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Stream Finishing For The Aerospace Industry

OTEC’s stream finishing machines can be a reliable, quick and cost effective alternative to manual finishing for the aerospace industry. Stream finishing can be used with servo valves, which are commonly used in aircraft flight control systems. These valves hydraulically operate aircraft ailerons, rudders and other control surfaces.

OTEC’s SF-Series Stream Finishing Machine

High friction and burr formation among a servo valve’s bushings and spools can lead to abrasion and wear, which can cause the valve to fail. Additionally, sharp or unevenly rounded edges can also impair a valve’s flow. When a servo valve needs to be replaced, it’s very important to guarantee consistency, safety and stability. These replacement parts are frequently post-processed by hand, which can be inefficient and unreliable. Manual processing is subject to human error and can be very time consuming and costly.

Servo valves are electromagnetically operated hydraulic ram valves consisting of a bushing, a spool and an electric control unit. The valve can open or close a variety of hydraulic circuits based on the position of the spool.

However, stream finishing servo valves with a consistent flow of media and strictly monitored parameters guarantees maximum process reliability and repeatability, which means a much lower rejection rate for parts. OTEC’s SF3/3 RLS stream finishing machine with an automatic workpiece loading system can process a component in 40 seconds flat. OTEC machines can pay for themselves in as little as two to three months. The pulse finishing process used with our stream finishing machines reduces cycle time by up to 96% compared to manual processing. Other benefits of OTEC’s high-precision processing include enabling the closest possible tolerance, which is critical for system tightness, and permitting a higher switching or stroke frequency, which significantly increases control accuracy. 

Before (Top) and After (Bottom) Stream Finishing

Pulse finishing, OTEC’s stream finishing innovation, has remained the fastest mass finishing process on the market since it was launched in 2013, with average process times of 60 seconds. Using very small grinding bodies compatible with the process, it produces precise, effective, ultra-consistent results even with complex workpieces. OTEC stream finishing systems are cost-effective, process-oriented solutions that combine easy automation with maximum process reliability.