About us

SIHN - A history of innovation.

Robert Sihn GmbH & Co. KG was established in 1939 by Mr Robert Sihn Sr. In 2012 the business was bought and continued as RSN Sihn GmbH. We have been operating in a leading position in the most quality sensitive and innovative areas of the automotive industry, such as power-assisted steering systems, fuel and oil systems, as well as active suspension systems. Our core competences are medium and high volume production of top-quality precision turned parts and assembly groups for selected automotive and industrial niche markets. With a combination of experience, sense for innovation, future-orientated engineering and flexibility we are able to meet the constantly rising demands of our customers. For fittings (connector, banjo bolts, fluidic elements), angle joints (mechanical elements), specific drawing parts as well as more complex components, customers from all over the world consider RSN Sihn a trustworthy strategic partner and appreciate the consistency of our high quality production.


Using TS 16949 as the underlying quality philosophy continuously improve the company, its products and business processes. Highly motivated employees with top-notch technical qualifications work on interdisciplinary projects with state-of-the-art technologies (e.g. CAD, FEM, CAM, CFD). This enables us to provide customized individual support to our partners and their specific requirements. Additionally, our well experienced R&D department offers customized solutions which can even be produced in high volumes.
SIHN has at the moment two production sites in Mühlacker and Lugwald.
We are proud to be a reliable and responsible equal opportunity employer for our workforce of about 500
employees offering above average opportunity for continued education and interesting and challenging career opportunities.

Top quality – always

Quality starts with raw material: wherever possible, we use raw material that has been tested for defects by both ultrasound and eddy current tests. Thereafter, modern equipment and optimized production processes ensure a constantly high product quality and process reliability. Supported by automated process data acquisition feeding into statistical process control systems, we constantly monitor and improve our production processes. This  production system enables us to meet even the most ambitious customer demands such as for complex geometries, surface quality or purity.

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Technical innovations

Decades of experience in our key production technologies (metal-cutting, machining, welding, cold forming, brazing) as well as our innovative approach to development and design in combination with our focus on environmentally friendly and low-pollutant processes are the key distinctive strengths of SIHN.

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Development, engineering design and technical consulting

Our work starts well before the start of mass production:

At the initial stage, a diligent examination of the design for technical feasibility and optimization potential in terms of cost and function is being made by our Product and Application Technology Department. Our engineers are also available for on-site consultation.

We always strive to closely synchronize our work on components and systems with the design and development process of our customers. Our engineers have experience in and are using most industry standard and state-of-the-art CAD systems (Inventor, CATIA V5, MD 6) ensuring a seamless data exchange with customers engineering departments. Our product development is supported by both numeric simulation tools (such as FEM & CFD) and our own test lab with capability for material testing (strength, hardness, structure) and test rigs for components and systems for criteria such as fatigue endurance, corrosion, leakage.

Prototypes and small-batch samples from complex swivels to complete component groups can be produced on short notice.

In-house competence and capability to design and manufacture production, assembly and test equipment, from a simple machine tool to complex processing machines ensures mastery of all relevant production processes. We consider this know-how in combination with co-operations with leading machining equipment manufacturers and research institutions to be a key competitive advantage.

SIHN is the official partner of the institute for production technology of the Technical University Darmstadt.

We'll do it for YOU!

With us everything is about partnership, fairness and trust to our customers.

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pdf klein   Portfolio 2017 DE

pdf klein   Company presentation 2017 DE