Rounding, Deburring, Flow Calibration: One Process, Meeting Three Technical Needs Simultaneously
KunshanJune 22, 2026 /PRNewswire/ — Recently, German hidden champion Sonplas launched the high-pressure liquid abrasive flow machining technology HERO (HydroEROsive machining), specifically applied to the precision machining of key components in internal combustion engine fuel injection systems, such as injectors, nozzles, common rails, fuel pump bodies, or pump heads. This technology not only achieves deburring and rounding of inner holes and inner diameters but also rounds the edges of inner holes with diameters as small as 0.1 to 5 millimeters, and performs flow calibration for different fluids. This precision fluid control technology provides suitable solutions for various high-pressure injection scenarios.
As the starting year of the “15th Five-Year Plan” in 2026, high-quality development and sustainable economy, such as energy conservation and emission reduction, have become key. In the automotive powertrain sector, new internal combustion engine gasoline direct injection technology is emerging, and high-pressure common rail fuel pump technology for diesel engines is also gaining more market favor. Sonplas’s important precision machining fluid control technology has become the core application support for continuously improving fuel efficiency in internal combustion engine injection systems.
High-Pressure Liquid Abrasive Flow Machining HERO (Abrasive Flow)
High-Pressure Liquid Abrasive Flow Machining HERO (Abrasive Flow)
In the high-pressure liquid abrasive flow machining (HydroEROsive, abbreviated as HERO) process, a fluid containing mixed abrasive particles is pumped under high pressure into the internal geometry of the component. This liquid abrasive flow method can be used for deburring and rounding, suitable for precision component processing in the automotive industry, and can also be used to calibrate the flow of bore diameters. Sonplas not only possesses extensive technical experience but also provides comprehensive system solutions to meet different application requirements.
“Even components with complex shapes often require internal grinding, rounding, or deburring,” said Werner Riederer, Sales Engineer at Sonplas GmbH, based in Straubing, Bavaria, Germany. In the automotive industry, such components include fuel injectors for internal combustion engines or injectors for hydrogen internal combustion engines. The HERO process is very suitable for these special applications. “Currently, more than half of the world’s diesel injection nozzles use this method for flow calibration,” Riederer explained.
The high-pressure liquid abrasive flow machining process enables efficient and controllable deburring or rounding of intersections of internal channels. This process significantly improves the high-pressure resistance of the component, minimizing wear even under extreme high-pressure environments, or significantly slowing down the wear process. Additionally, this process can simulate artificial pre-aging of the component, allowing users to obtain consistent and stable performance throughout the entire service life of the part. Deburring is not only related to the functionality of the part but may also be used to improve ergonomic design or enhance appearance quality.
In this process, the fluid containing abrasive particles flows along the intersections of channels or the geometry of bore diameters inside the workpiece, similar to liquid sandpaper. Werner Riederer illustrated with an example: “Suppose a channel with a diameter of 2 millimeters gradually narrows to a channel of 1 millimeter, forming a sharp edge at the constriction point. Under high pressure, the abrasive particles will accumulate at this point and remove material. The amount of material removed depends on the fluid pressure and the type of abrasive particles used.”
Flexible Component Selection
Before Processing – After Processing: Example of High-Pressure Liquid Abrasive Machining. Here, the injection holes of an injector made of nickel-based alloy have been rounded.
The range of workpieces that can be processed is extensive. Werner Riederer stated: “The key factor is always the size of the bore diameter to be processed. Our system can grind holes with diameters ranging from 0.1 to 5 millimeters.” For example, nozzle holes and other holes in fuel engine injection systems can also be rounded. The workpiece material can be steel or stainless steel, while aluminum, magnesium, and precious metals such as gold, silver, and platinum are also applicable. Additionally, cemented carbide, such as materials used for cutting tool inserts, as well as glass, ceramics, plastics, and fiber composites, can also be processed.
Optimized and Customized Process Media
The characteristics of the process media are first specifically adjusted according to the requirements of the workpiece to be processed: by optimizing rheological parameters to achieve the desired flow rate, geometry, and degree of rounding. Depending on the application, the process media can be formulated on a mineral oil or water base and adjusted to a viscosity range from 0.5 to tens of thousands of mPa•s (millipascal-seconds).
The type, concentration, and particle size distribution of the abrasive particles in the media play a crucial role in determining the material removal rate and the surface quality of the workpiece. High-hardness ceramic materials, such as boron carbide, aluminum oxide, or even synthetic diamond, can be used as abrasive particles. Werner Riederer explained: “This versatility allows us to process different components within optimized cycle times.”
Furthermore, through specific additives, the abrasive fluid can provide effective corrosion protection for the customer’s workpiece after processing. Its excellent wetting properties and compatibility with flushing and testing fluids allow particles that are difficult to remove by other methods to be easily flushed away. Through intelligent process design, cleanliness levels specified by VDA19/ISO16232 can be met, thus avoiding additional expensive post-processing steps.
Sonplas also offers a water-based version of the “traditional” process media, which offers multiple advantages: environmentally friendly, hygienic, and with a low carbon footprint. Additionally, since it poses no risk of contaminating groundwater, waste fluid disposal costs are also lower.
Safe and Precise Flow Calibration
In addition to rounding and deburring, the HERO process can also be used for flow calibration of channels. In this process, the user selects a low-viscosity fluid. Werner Riederer illustrated with an example: “In engine technology, after the injection nozzle bore diameter has been processed by electrical discharge machining, its flow rate is 900 ml/min. We place this component into the system and round the inlet edge of the injection hole, increasing the flow coefficient by 10% to 40%.” After the HERO process, the flow rate of this nozzle can reach 1,000 ml/min.
The significant advantage of this process is: the flow rate scatter after electrical discharge machining is ±3%, while after the HERO process, the scatter accuracy can be improved to ±1%, greatly enhancing flow consistency and control precision. Through liquid abrasive machining, users can precisely calibrate the flow rate of the workpiece and monitor flow changes in real-time throughout the process, accurately adjusting to the target value, while setting the flow tolerance range with reliable process control.
Whether for deburring, rounding, or flow calibration, high-pressure liquid abrasive flow machining offers three different application solutions. Users can adjust the corresponding parameters according to their needs, ensuring high reliability and repeatability for various processing tasks. Sonplas expert Riederer concluded: “This process fully complies with all drawing requirements and part specifications.”
Customized Systems
Sonplas offers a variety of customized high-pressure liquid abrasive flow machining systems
Sonplas can also equip the system with a rotary table, allowing processes such as grinding, flushing, and/or flow measurement to run in parallel. Depending on requirements, each workpiece can pass through up to eight stations, with the longest cycle time determining the overall cycle time. Users can modularly customize the equipment according to their needs and integrate process stations such as flushing or measurement in later stages. Additionally, the system can be connected to databases and MES systems, and through DMC (Data Matrix Code) marking, full traceability of processing and process data is achieved.
Tina Yu, Sales Manager of Sonplas China, introduced: “The system also provides flow control and master parts. The integrated software introduces master parts into the process flow at set intervals and performs regular inspections.”
Since the equipment operates within a closed system, human operational errors do not occur. The operator only needs to complete manual loading or change pallets, and the entire process can run automatically and stably. For higher production volume requirements, the system also supports automated loading, for example, equipped with a robot loading module.
Tina further explained: “This configuration can also achieve process linkage. For example, the loading module can be placed after electrical discharge machining or laser drilling, and before HERO processing. This way, the customer only needs to load the workpiece, and finally, they can take out the parts that have been drilled, deburred, or flow-calibrated from the other end of the system, neatly placed on a pallet.”
She emphasized: “We can provide customers with comprehensive solutions ranging from basic processing equipment to high-volume production systems, fully tailored to customer needs.”
This precision finishing process of high-pressure liquid abrasive flow machining (abrasive flow) has been widely applied in multiple industries. Besides automotive, it is also used in aerospace, watchmaking, and medical technology fields. For special applications such as implants in the medical field, micro parts in the watchmaking industry, high-frequency technology components, or cooling channels in special screws, high-pressure liquid abrasive flow machining HERO is particularly suitable. We look forward to this technology being applied on a larger scale in key industries of the “15th Five-Year Plan,” such as aerospace, medical, semiconductor, marine, and wind energy.