Jokin Juaristi, General ManagerEngranajes Juaristi specializes in manufacturing gears to customer specifications in highly variable one-off and small-batch production environments. It combines advanced grinding technology, controlled manufacturing conditions and operator-driven flexibility to achieve precision levels expected from serial production environments.
“Our core business is the manufacturing of complete gears, but the real added value lies in the precision we can achieve,” says Jokin Juaristi, general manager.
With nearly half of its production consisting of single-part orders, Engranajes Juaristi is able to consistently maintain tolerances as tight as three microns, with finishing corrections possible down to a single micron. This level of precision is critical for applications in wind energy, railway systems, industrial gearboxes and machine tools, where gear meshing accuracy, operating noise, durability and long-term reliability directly affect system performance under load.
Precision Driven by Operator Expertise
Engranajes Juaristi’s ability to maintain precision in highly customized production environments is anchored in the expertise and adaptability of its operators, who assume substantial responsibility for day-to-day manufacturing decisions. Even with highly advanced machining systems, operators spend a significant amount of time preparing and adjusting setups because production requirements can shift dramatically from one job to the next.
Our core business is the manufacturing of complete gears, but the real added value lies in the precision we can achieve.
A gear with a diameter of 1000 mm may be followed immediately by a component measuring only 50 mm, requiring major adjustments to tooling, clamping systems and machine configurations. Operators manage programming, setup, tooling and coolant adjustments throughout these transitions, maintaining both flexibility and precision across highly varied production requirements. In many cases, maintaining quality depends as much on operator expertise as on the machining systems themselves.
Grinding represents the final and most critical stage of gear manufacturing, with its quality directly influencing how reliably a component performs under operating conditions. One of the biggest challenges during grinding is the risk of thermal burn, where excessive heat generation reduces the hardness achieved during the previous heat-treatment process. Although the damage may not always be visible on the surface, the loss of hardness can significantly affect long-term component performance.
To control this risk, Engranajes Juaristi invests in advanced grinding tools, tooling technologies and controlled machining parameters designed to prevent grinding burn, improve machining efficiency, reduce machine downtime and shorten machining cycles. Because grinding is the final manufacturing operation, preventing scrap at this stage is particularly important. A damaged component can affect delivery schedules, require the manufacturing process to restart and delay shipment to the customer.
Quality control is integrated directly into the production workflow. Dedicated inspection teams monitor both in-process operations and final measurements, while production, planning and quality teams coordinate whenever a deviation appears. The rapid response process helps address issues early, minimize delivery delays and ensure components meet the required standards before shipment.
Reverse Engineering Focused on Real Operating Conditions
When critical equipment components fail, and original specifications are no longer available, replacing the entire system is rarely the most practical or cost-effective solution. In these situations, reverse engineering the failed component becomes a key part of the service.
In most cases, customers provide the technical drawing, and as an outsourcing manufacturing partner, Engranajes Juaristi produces components entirely to specification. When no drawing or documentation exists, it develops technical drawings based on critical measurements to accurately reproduce the original shape and functionality, particularly in situations where the customer may not fully know how the component was originally designed.
“At that point, the project becomes more like a small design collaboration,” says Juaristi.
The process starts with a physical analysis of the existing part. Engineers measure critical dimensions, create technical drawings and test material properties such as hardness levels. The assessment then focuses on how the component operates within the customer’s system and whether targeted improvements can be introduced during the remanufacturing process.
Using gear calculation software and engineering analysis tools, adjustments may be proposed to tooth geometry, flank profiles or hardness specifications based on the operational conditions the client describes. Even relatively small changes can improve wear resistance, reduce noise, or distribute load more evenly across the gear surface.
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At that point, the project becomes more like a small design collaboration.
Successful reverse engineering depends heavily on customer collaboration, as operating conditions and application-specific requirements play a critical role in determining how effectively the component can be optimized.
Before delivery, components are tested on dedicated bench systems to confirm functionality and dimensional accuracy.
Performance improvements are not always directly measurable from Engranajes Juaristi’s side, as final validation takes place within the customer’s operating environment. Although components are manufactured to fulfill customer specifications, in some cases, the quality achieved during manufacturing enables customers to obtain better-than-expected results. The outcomes may include lower operating noise, longer service life or overall performance that exceeds the original expectations established during design and testing.
Expanding Precision Manufacturing with Long-Term Sustainability
Engranajes Juaristi is expanding its international presence through representatives across multiple European countries while also developing new partnerships in global markets. Spain and Germany remain the company’s strongest and most established markets.
Alongside its growth strategy, it places strong emphasis on quality, safety and environmental responsibility in line with European ESG objectives and 2030 sustainability goals. Recent initiatives include the installation of solar panels that reduce electricity costs by approximately 30 percent in an operation heavily dependent on electrically powered machinery.
It has also introduced a water recovery and purification system to reduce industrial wastewater generation. Previously, nearly eight tons of wastewater required annual external treatment due to contamination concerns. The new recovery system now allows approximately 96 percent of the water to be recovered and reused with minimal loss, significantly improving both resource efficiency and environmental performance.
Driven by precision, manufacturing flexibility and continuous investment in quality, Engranajes Juaristi continues expanding its presence across Europe while strengthening the manufacturing capabilities that support demanding industrial transmission applications.
