Diehl Metal Forgings

• 768 Employees
• € 135 million Sales per year (in 2024)
• 50 million Synchronizer rings per year as world market leader
• 6 million Formed parts produced per year with a special brass content of 70%

Segment Formed parts

• Lead-free brass housings for water meters

  

  Innovative. Safe. Future-proof

  Lead-free brass housings for water meters – precisely manufactured in Germany. In times of strict drinking water regulations, 100% lead-free housings are no longer an option, but mandatory. Our high-quality meter housings meet the highest requirements in terms of material quality, durability and sustainability.

  • Drinking water compliant & certified: globally recognised in accordance with the current Drinking Water Ordinance.
  • Highest precision: CNC machined, tight tolerances, perfect surfaces and durable threads.
  • Durable & corrosion resistant: for over 15 years of reliable use under changing conditions.
  • Sustainable: recyclable lead-free brass, CO₂-optimized production in Germany.
  • Flexible: suitable for ultrasonic, jet and piston meters from DN 15 to DN 50, with all common connections and special variants.

  We don't just supply housings – we accompany you as a reliable development partner.

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• Sliding Elements & Bearing Solutions

  

  Precision under pressure

  We supply wear-critical precision components made of lead-free brass, bronze and aluminium-bronze for axial and radial piston pumps, gear pumps and hydraulic motors of the latest generation – including high-precision bushings. Our core components: sliding shoe/piston shoe, retaining and distribution plates, bushings & bearing rings as well as complex forming and turning parts – all from a single source, tribologically optimised and suitable for all media.

  Why leading hydraulic manufacturers rely on us:

  • 100% lead-free & RoHS/REACH compliant, without compromising on mechanical precision.
  • Highest accuracy: fits and surfaces directly from the machine, even with thin-walled bushings.
  • Completely in-house: from toolmaking and hot forming to CNC turning/milling and cleanroom packaging.
  • Fast from idea to series production: prototypes and series tools in weeks thanks to in-house design and simulation. 

  Whether mobile machines, industrial drives or sustainable fluid technology – our sliding elements make hydraulic power units more efficient, quieter and more durable.

   

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• Thrust Bearing

  

  Precision at 200,000 rpm⁻¹

  Our high-precision thrust bearings made of lead-free brass or special bronze alloys ensure maximum performance and dynamics in passenger car and commercial vehicle turbochargers as well as industrial applications. Optimized ramp and oil distribution geometries minimize friction and ensure maximum load-bearing capacity – proven millions of times over.

  • 100% lead-free & compliant: ELV, RoHS and REACH – ready for series production and environmentally friendly.
  • Maximum load capacity: For downsizing engines, hybrid drives and sophisticated turbochargers.
  • Precise bushings & bearing rings: Thin-walled, extremely pressure-resistant, perfect fit for shaft and housing.
  • Fast development partners: From the first geometry to PPAP in just a few months, including fully automated production and 100% control.

  Unleaded is not a topic of the future for us – but a reality for millions of kilometres.

   

   

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• Large forgings

  

  Heavy-duty, precise, lead-free

  We manufacture large forgings made of brass, lead-free brass, bronze, copper and special alloys up to 35 kg – Made in Germany. State-of-the-art forging presses with up to 1,000 tons of pressing force are used to produce high-strength, tribologically optimized components for valves, fittings, shipbuilding, offshore, energy generation, special gearboxes, and railway applications.

  • Lead-free & compliant: Drinking Water Regulation, ELV, RoHS and REACH without compromising on strength and machinability.
  • Optimal material utilization: Drop forging produces perfect fiber alignment, higher strength than casting and minimal post-processing.
  • Complete process chain under one roof: toolmaking, hot forming, heat treatment, mechanical processing and 100% crack testing.
  • Flexible & economical: From small to large series, fast tool availability and prototype validation through simulation.

  Large, lead-free and resilient – this is our daily reality.

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• Copper Forgings

  

  Precise. Conductive. Reliable.

  As a German specialist, we manufacture highly conductive forgings made of pure copper, OF-Cu, Cu-ETP and other copper alloys for lightning protection, earthing technology, occupational safety and industrial electronics. Our forgings offer the highest electrical conductivity, optimized mechanical strength, and lead-free environmental compliance.

   

  • Maximum conductivity: up to 101% IACS for pure copper, even after hot forming and heattreatment.
  • Mechanically highly resilient: perfect grain flow, higher fatigue strength than with casting or extrusion.
  • Complete production chain: toolmaking, hot forming up to 1,000 t, CNC machining, conductivityand hardness testing.
  • Economical & flexible: Prototype to large-scale production >100,000 pieces/year, fast tool availability, lower material costs and rejects.

   

  Forging instead of casting – for copper parts that transport electricity reliably and efficiently.

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Segment Synchronizer Rings

• Synchronizer Rings

  

  One Gear Ahead

  As the first partner of the international automotive industry, we develop and manufacture high-performance synchronizer rings made of brass and steel for all transmission applications. Our products impress with their exact geometry, high wear resistance and maximum strength – for reliable shifting performance under all conditions.

  • Brass synchronizer rings: made of special brass alloys, also lead-free, optionally with threaded design or carbon friction lining for the highest requirements.
  • Steel synchronizer rings: formed, with carbon friction lining, proven millions of times.
  • Multiple synchronizations: single and multi-cone synchronizations, tailored to your application.
  • Tailor-made solutions: technically convincing, economically attractive, available worldwide, with in-house development and test bench expertise.

  With Diehl Metal Forgings, you stay one gear ahead – for durable, precise and high-performance transmission components.

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Segment Stamping Parts & Busbars

• Stamping Parts & Busbars

  

  Precise. Efficient. Reliable.

  We manufacture high-precision stamped parts for transmissions and busbars for batteries – for automotive applications as well as for industrial systems. With over 40 automatic stamping machines, progressive and transfer tools as well as high-performance stamping and forming presses up to 800 tons, we produce complex components in small and large series, including prototypes. Our customers particularly appreciate our tailor-made solutions, which are technically convincing and economically attractive. 

  Our competencies for your project:

   

  • Wide range of materials: steel, stainless steel, aluminium, copper, bronze, brass, special alloys and bi-metals
  • Precise manufacturing: complex geometries, tightest tolerances, maximum technical cleanliness
  • Flexible processes: machining or chipless, highly complex assembly technology, in-house toolmaking

   

  With a global presence, we supply and support directly on site and offer economically efficient stamped parts that significantly reduce material, time and costs compared to purely machining processes.

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Manufacturing

• Forming Technology & Machining

  

  Precision in form and dimension – forming technology and machining from a single source

  At Diehl Metal Forgings, we rely on state-of-the-art cold and hot forming processes to produce high-quality formed parts with the highest form, position and dimensional accuracy as well as optimal surface quality. Our versatile machinery and equipment enables (near) Netshape products, reduces material consumption and minimizes downstream processing steps.

  • In hot forming, we produce parts from a few grams to 35 kg on fully automated forging systems from 100 t to 1,100 t, including heat and surface treatment. Complex hollow pressed parts, such as those required for water meter housings, are also part of our production spectrum.
  • In cold forming, we implement sophisticated multi-stage processes such as punching, bending, upsetting and extrusion – both on progressive and transfer tools. Press forces of up to 8,000 kN enable the production of precise components from strip material or piece material.
  • Thanks to state-of-the-art CNC machining with integrated measuring technology, we also offer the machining of our formed parts – even for special alloys such as lead-free or low-lead materials. Our globally uniform manufacturing standard guarantees the highest quality at all locations.

  With forming technology and machining from a single source, we offer our customers economical, sustainable and technically excellent solutions – uniform and reliable worldwide.

  About forming technology

Development & Engineering

• Design & Toolmaking

  

  Thanks to the close cooperation between design and toolmaking, we are able to carry out all steps from CAD design to the finished tool in-house in an integrated tool development process. This allows us to implement new productions as well as changes to tools at short notice. This results in clear advantages for the customer:

  • Short-term adaptation of tools
  • Tool-falling components already in the prototype phase
  • Increased flexibility
  • Optimization of tool life

  About toolmaking at Diehl Metall

• Integrated Value Chain

  

  For special applications as well as individually manufactured components, we work with customers and partners to develop specific solutions in order to select the appropriate materials and to define tailor-made material combinations and manufacturing processes. As a system supplier, we offer extensive knowledge, experience and know-how in all areas of the production process.

  About integrated value chain at Diehl Metall

• Quality Management

  

  We have a certified quality management system in accordance with international quality standards. Quality management is an integral part of the process chain to ensure all aspects of quality assurance in the interests of the customer. The focus is also on the continuous optimization of our business and production processes.

  • Quality: IATF 16949 and ISO 9001
  • Environment: ISO 14001
  • Energy: ISO 50001

  About Quality at Diehl Metall

• Product and Process Development

  

  Laboratory & Materials Testing

  The function and service life of the formed parts depends on the material, the geometric design and the optimal interaction of the individual component components. To obtain the best possible solution for the respective requirements, we offer a versatile range of test methods:

  • Hardness testing
  • Metallography
  • Microhardness testing
  • Quantitative structural analysis
  • Tensile test
  • Chemical analysis
  • Scanning electron microscope
  • EDX-Microanalysis

  In addition, we also carry out special investigations as part of development projects and advise our customers on all material issues.

• Röthenbach Diehl Metall Schmiedetechnik

  Core competencies:

  • Formed parts
  • Brass Synchronizer Rings
  • Steel Synchronizer Rings
• Wuxi Diehl SynchroTec

  Core competencies:

  • Steel Synchronizer Rings
  • Brass Synchronizer Rings
  • Sliding Surfaces
• Sao Paulo Diehl Do Brasil

  Core competencies:

  • Brass Synchronizer Rings
  • Sliding Surfaces
• Pune Diehl Metal India

  Core competency:

  • Brass Synchronizer Rings

   

• 2025 A Piece of History Leaves the Press

  

  In November 2025, the last brass synchronizer ring was produced at the Röthenbach site. Since the first production in 1956, this component has represented precision and quality at Diehl Metal Forgings for more than six decades.
  With over 1.8 billion synchronizer rings manufactured, this era in Europe has come to an end – paving the way for new products, materials and future technologies.

• 2023 Excellence in Sustainability Management

  

  In 2023, Diehl Metal Forgings received the EcoVadis Silver Medal for its sustainability performance, following the Bronze award in the previous year. The company achieved outstanding results in sustainable procurement and ethics, placing it among the top 9% of companies evaluated worldwide.

  
  The award confirms its strong commitment to environmental protection, human rights, ethics and responsible supply chains.

• 2016 Milestone for synchronizer rings

  

  In 2016, Diehl SynchroTec will produce 27.3 million steel and brass synchronizer rings for the Asian market – more than ever before.

• 2015 New Steel Synchronizer Ring Manufacture in China

  

  At the Wuxi site, steel synchronizer ring production will be put into operation in 2015. In addition to brass synchronizer rings, Diehl SynchroTec now also produces steel synchronizer rings directly on site. The foundation stone for this expansion was already laid in 2013, when the company premises were enlarged by 11,000 m2 with an extension.

• 2012 Founding of Diehl Metal India

  

  Diehl Metall establishes Diehl Metal India in 2012, thereby strengthening its global activities. Synchronizer rings are produced locally for globally and locally active automotive OEMs and transmission manufacturers in India.

• 1998 - 1999 Technology change with foresight: Return to salt bath hardening

  

  In the late 1990s, Diehl Metall Schmiedetechnik made a landmark decision: The originally planned conversion of all hardening processes to vacuum technology could not meet the high requirements for component quality and tool life.

  After intensive analysis, the decision was made to use the proven process of salt bath hardening – modernized and optimized together with the partner Durferrit. This made it possible to ensure hardness quality, significantly increase tool life and noticeably expand capacities in the field of heat treatment.

  This strategic realignment not only improved process stability, but also laid the foundation for further growth.

• 2007 Diehl now also produces steel synchronizer rings

  

  Brass synchronizer rings for the automotive industry have been one of Diehl Metall's successful products for fifty years. The number of rings produced has long since exceeded the billion mark. As the demands on synchronizer rings continue to increase due to ever higher engine outputs, speeds and torques, the trend is towards steel synchronizer rings with new, wear-resistant carbon friction layers, especially in the upper vehicle segments.

  In 2007, Minister-President Dr. Günther Beckstein will be able to open a new steel synchronizer ring production facility from Diehl Metall in Röthenbach to meet the growing demand. In total, the investments in recent years at the Röthenbach metal site amount to around 50 million euros.

• 2003 Ausbau der globalen Aktivitäten

  

  With the founding of Diehl SynchroTec Manufacturing in Wuxi in 2003, Diehl Metall has set its sights on the strategically important market of China in order to be able to supply local automotive companies with synchronizer rings quickly and flexibly.

• 2000 - 2001 Restructuring and turn of the millennium

  

  The social structure of the group of companies, which has grown over decades, will be adapted to the company's decentralised management structure. In the future, Diehl will consist of the four subgroups Metal, Controls, Equipment and VA Systems. The Equipment subgroup is integrated into Diehl VA Systeme in 2001.

  In the course of the restructuring, Röthenbach will become the headquarters of the Diehl Metall subgroup.

• 1985 - 2000 Continuous expansion of environmental protection

  

  In the mid-80s, environmental protection in Röthenbach was systematically expanded. A heat recovery system will be installed in the foundry to save energy. Furthermore, a wastewater neutralization and a detoxification plant for the neutralized chrome pickling will be built.

  The investment-intensive measures not only help to save energy and reduce costs, but in 2000 the Metal Division is also awarded the European Union's environmental audit for its ecological standards at the Röthenbach site.

• 1970 - 1979 Expansion of the classic production areas

  

  In the 70s, the classic production areas at Diehl are further expanded. In the course of this, the structural expansion of the drop forge by 5,500 square meters in Röthenbach will take place. In addition, another pipe press with a pressing force of 2,350 tons will be installed.

• 1970 Founding of a plant in Brazil

  

  With the acquisition of an automotive supplier in Saõ Paulo (later Diehl do Brasil Metalúrgica), Diehl is able to bundle its increasing semi-finished products activities on the American market and rapidly expand them through local production. Over the years, Diehl do Brasil developed into an important Brazilian producer of pressed parts and a supplier for automotive and transmission manufacturers on the American continent.

• 1956 Start of synchronizer ring production

  

  In addition to semi-finished products, Diehl was also increasingly producing forgings at this time. In 1956, the company began production of synchronizer rings and produced the first synchronizer ring for the synchronization of manual transmissions in automobiles.

• 1950 - 1959 Realignment in the development years

  

  In the post-war years, new production processes and changing demand patterns necessitated a conversion of production facilities to high-quality copper and brass products.

  In the course of this realignment, Plant 1 is shut down and comparatively generously dimensioned production facilities with modern machining centers are built in Röthenbach. The main buyers of the products in the early years are the automotive industry, but also the sanitary industry.

• 1945 Reconstruction and new beginnings

  

  After the end of the war, the Diehl company faces unprecedented challenges. For a while, dismantling and reconstruction run side by side.

  As temporary employment, repair work was initially carried out on Reichsbahn wagons and utensils such as ladles and pots were produced by remelting light metal scrap.

• 1939 War events and destruction

  

  In 1939, the company was classified as a company important to the war effort. In 1944, almost all buildings in Röthenbach were destroyed or severely damaged by air raids.

• 1935 - 1938 Founding of a new semi-finished products plant in Röthenbach

  

  A lack of expansion possibilities on the site of Plant 1 made it necessary to establish a new casting and pressing plant (Plant 3) with a drop forge in Röthenbach, just outside Nuremberg. In 1938, a 3,500-ton press went into operation here, at that time the largest of its kind in Germany.

• 1914 - 1917 Growth and upheaval during the First World War

  

  The beginning of the First World War brought the Diehl company the change from the production of handcrafted consumer products to the casting of brass rods. From this, raw parts for ammunition production are pressed in the company's own drop forge.

  As early as 1914, a drop forge and a turning shop with toolmaking were established in Nuremberg.

• 1902 It begins with a small art foundry

  After his years of apprenticeship and travel, he ended up in Nuremberg, which increasingly developed into a centre of the metalworking industry. With craftsmanship, innovative spirit and entrepreneurship, Heinrich Diehl founded his own "Arts and Crafts Model Workshop" in Nuremberg's Schweiggerstraße in 1902. For the small art foundry, the initial focus is on the production of models for furnaces, art and construction castings as well as epitaphs (grave slabs).

• 1900 Founding years

  

  The story begins in the 19th century – a time of new beginnings. Industrialization fundamentally changed people's lives. The young Heinrich Diehl, son of a farmer, was also fascinated by the possibilities offered by metal as a material. He decided to start an apprenticeship in metalworking – and thus take the first step towards the company's history.

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