Dango & Dienenthal

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File:Dango & Dienenthal Logo 2025.svg
Type	Private
ISIN	🆔
Industry	Machine construction Filtration technology
Founded 📆	June 1, 1865 (1865-06-01) in Siegen, Germany
Founders 👔	August Dango, Louis Dienenthal
Headquarters 🏙️	Hagener Str. 103, 57072 Siegen, Germany
Area served 🗺️
Key people	Jens-Uwe Heitsch, Alexander Neff (Managing Director, Operational Management)
Operating income	€ 160,5 Mio. (2023)
Members
Number of employees	>850 (2025)
🌐 Website	dango-dienenthal.com
📇 Address
📞 telephone

Dango & Dienenthal (D&D) is a German machine construction company based in Siegen. It specializes in the development and manufacturing of special machinery and plants for metallurgy, including the melting, forging, rolling, bending and heat treatment of semi-finished products made from steel and non-ferrous metals. Dango & Dienenthal is also active in the field of filter technology, offering filter systems for liquids in various industries. The traditional company is currently managed by the fifth generation, having made a significant contribution to the development of the metal industry.

History

August Dango and Louis Dienenthal

August Dango and Louis Dienenthal

Formation and growth (the 1st generation: 1865 – 1900)

Dango & Dienenthal was founded on 1 June 1865 by August Dango (1837 – 1924) and Louis Dienenthal (1838 – 1906) in Siegen as a non-ferrous metal foundry and turning shop that manufactured small cast metal fittings from bronze and red bronze. The company was officially entered into the register of companies on 16 July 1865.

In 1871, the company acquired its first steam boiler, enabling the production of larger fittings and iron/machine castings. In 1874, Dango & Dienenthal obtained a license to manufacture phosphor bronze, a hard, more resistant material. That same year, the company started producing blow molds from copper blocks. Developing further, the company began to produce blast furnace blow molds, rolling element bearings and acid-resistant pickling baskets in addition to fittings. Between 1880 and 1885, Dango & Dienenthal launched water-cooled hot blast valves for blast furnaces onto the market, an innovation offering an improvement to the customary closure devices of the day.

By 1883, the company employed more than 30 people, supplying customers abroad as well as the German market. The company played an important role in the development of the iron and steel industry and foundry technology in the 19th century. From 1885, the factory began to expand extensively. A subsidiary was founded in Ottange (Lorraine), the first branch factory for the production of blast furnace fittings. The company had already been supplying customers in Eastern Europe since the 1870s, primarily Vítkovice Mining and Iron Corporation in what was then Austria-Hungary (now Ostrava, Czech Republic). In 1886, a second subsidiary was founded there, led by Julius Dango (1843 – 1902) and focusing on blast furnace, water and steam fittings. In 1895, a coppersmith's workshop was affiliated to manufacture forged blow molds.

By 1890, the number of employees at the parent site in Siegen had grown to between 40 and 50 people. In addition to the Siegerland, the company was supplying the Ruhr Area and Saarland. In 1889, the second generation took over the management of the company, including Julius Dango (Vítkovice) and Willi and Otto Dienenthal. In 1897, a further subsidiary was founded in Saint-Léger (Belgium) to avoid high import duties; it supplied customers in France, Belgium, Luxembourg and Russia. In 1899/1900, a new foundry was set up in Siegen.

Catalog 1880

Catalog 1880

Expansion and international focus (the 2nd generation)

When founders August Dango and Louis Dienenthal retired in 1899 and 1901 respectively, the 2nd generation took over the management of the company. Within around 35 years, Dango & Dienenthal developed from a small factory to an internationally active company with subsidiaries in many of Germany's neighboring countries. Its products were marketed in several languages to reflect the international focus.

Around 1900, the plant had its own steam engine with a DC generator to supply power, and used compressed air and electric motors with belt drives. This is when the production of the first machines began, including pneumatically operated taphole closing machines. In 1905, the company developed its own process for manufacturing drawn blow molds.

The Nazi era (the 3rd generation)

1936 saw a further generation change at Dango & Dienenthal: Bernhard Dango (1902 – 1981) and Herbert Dienenthal (1904 – 1994) took over the management of the company, converting it into a "Kommanditgesellschaft" (limited partnership). They strengthened the company's focus on machine construction, with Herbert Dienenthal's experience from the United States proving useful for technical optimizations and improving efficiency. Standards and bills of materials were introduced, blow mold production was improved, and dated machines were replaced.

Witkowitz metal foundry around 1933

Witkowitz metal foundry around 1933

The first charging machine was manufactured in 1933, and in 1936, the first forging manipulator was produced. It had a 2 t bearing load and was delivered to the Soviet Union. The subsidiary in Vítkovice, specializing in blast furnace accessories, also saw positive development, expanding its customer base to Bohemia and sometimes employing more people than the parent company in Siegen.

Bernhard Dango took on the management of the Vítkovice subsidiary, while Herbert Dienenthal remained in Siegen. Shortly before the German offensive in 1941, D&D Vítkovice was completing major orders for the Soviet steel industry. An office extension and employee facilities were built in Siegen in 1938/1939; there were around 250 employees. The order books were full, but in 1939 the war arrived, along with a shortage of raw materials, loss of personnel due to conscription, and restricted export opportunities. The company produced machines that were important for the war effort but had no preferential access to resources.

Destruction and post-war rebuilding

During World War II, the Dango & Dienenthal plant suffered heavy damage in the 1944 air strikes. By the end of the war, it was practically non-existent. The production plants and the historic home of the founding family had been destroyed. After the war, rebuilding started under the direction of Herbert Dienenthal and Bernhard Dango, despite difficult conditions and a restricted production permit from 1947.

The long-running license contract with US company Brosius was terminated after the war, after which D&D continued to develop the machines independently. Economic recovery and the currency reform of 1948 enabled a comeback, facilitated by new licenses and entry into the filtration and ferroalloy sectors.

Modernization and restructuring (the 4th generation)

During the 1950s and 1960s, major modernizations and extensions were made to the company buildings, and the production of blow molds, which the company had manufactured for over 100 years, was discontinued (1963–1965). In 1965, the company celebrated its 100th birthday. It now had around 260 employees and an export ratio of about 50%. At this time, D&D supplied steel, copper and ferroalloy plants around the world, including markets in Europe, America, Africa, Asia, and Australia.

In the 1960s and 1970s, the 4th generation of the two families joined the company: Manfred Dango (born in 1935) took over the management in 1969, and Jörg Dienenthal (born in 1943) entered the company in 1973. Both had been educated internationally, particularly in the United States and Great Britain. Under their leadership, Dango & Dienenthal developed into a globally recognized brand for machine and plant construction in the metallurgy sector. The range of products included taphole closing and drilling machines, blast furnace horizontal measuring probes, skimming machines, charging and poking devices, and manipulators and tool changing systems. The company also operated as a licenser for international partners in Japan, England, the United States, India, Brazil and Czechoslovakia. In 1978, the company was organizationally divided into a holding company (Dango & Dienenthal KG) and an operating company (Dango & Dienenthal Maschinenbau GmbH). In the years to come, further subsidiaries were established abroad, including in South Africa in 1982.

In the mid-1970s, Dango & Dienenthal developed into a globally active company in machine construction for the metallurgical industry, boasting a broad product portfolio and an international network.

International presence

During the 1980s, the company expanded its international presence: In 1982, a subsidiary was founded in South Africa. Led by Garry Hartz and, later on, Hannes Goosen, it became the market leader in machines for the ferroalloy and blast furnace sector. In 1986, this was followed by a subsidiary with its own production facilities in the United States; however, this was scaled down around the year 2000 due to losses. The subsidiary was expanded again in 2024, taking over the sales and service activities of Dango & Dienenthal Maschinenbau GmbH, Dango & Dienenthal Filtertechnik GmbH and Hencon B.V.

At the parent site, the office spaces and assembly hall were expanded to enable the production of larger machines up to 265 tons. In 1990, the filtration division was split off into a separate subsidiary. German reunification opened up new markets in Eastern Europe and the former Soviet Union, economically strengthening the company. In 1991, Dango & Dienenthal was briefly criticized as a result of a supply contract for Iraq, but was able to rebut the accusations. At the end of the 1980s, production was gradually digitalized with the introduction of CAD and CNC engineering.

In 1994, D&D Maschinenbau GmbH was one of the first medium-sized German companies to introduce a quality management system in accordance with DIN EN ISO 9001. In 1994, the company patented a three-point bearing for large manipulators. This development gave the company a unique selling point in the heavy manipulator sector.

Cooperations and innovations (the 5th generation)

At the end of the 1990s, more subsidiaries were founded: Service GmbH in 1998, a production facility in India with around 25 employees in 1998, and a sales and service company in Japan in 1999. At the start of 2001, Manfred Dango passed the management of the company to his son Rainer Dango (born in 1963). In 2009, Arno Dienenthal (born in 1973) joined him. They are the 5th generation of the company.

By the year 2000, Dango & Dienenthal had established itself as an internationally active company with an enlarged product portfolio and a global market presence. In 2003, the company entered into a strategic cooperation with its Luxembourgian competitor Paul Wurth in order to bring the intensive price war in the blast furnace sector to an end. This cooperation led to the Tapping Measuring Technology (TMT) joint venture, with sites in Siegen and Luxembourg. TMT brings together the know-how of both companies, and the venture is now the global market leader in the tapping technology sector. Production mainly takes place at Dango & Dienenthal in Siegen. TMT acquired Kring Transfer Technologie (TWT Kring, now Oventrop Energy & Network) in 2009, which allowed TMT to expand and become involved in research projects for the further development of hammer drills and acoustic measurement technology.

In 2015, Dango & Dienenthal Umformtechnik GmbH was founded. This expanded the product portfolio to include roll benders for large and thick sheets and induction benders for thin-walled and thick-walled pipes, particularly those with large diameters. Automated handling technology for heat treatment was also added to the range of products. In the same year, the Dutch company Hencon B.V. became part of the Group, rounding off the portfolio with machinery and equipment for the aluminum industry, mining and forestry.

Jens-Uwe Heitsch and Alexander Neff joined the management of the company in 2023. Rainer Dango and Jörg Dienenthal are continuing the traditional family history as shareholders. Andreas Dango, co-shareholder of the Group and managing director of TMT (as of 2023) completes the management of the company.

Innovations since 2015

• 2015 heralded the extensive use of Industry 4.0 technologies for mobile machines, with telemetry boxes transmitting machine data for analysis purposes.
• The first forging manipulator with an energy recovery system (ERS) was introduced in 2018.
• In 2020, the "D&D Connect" digital online portal was launched for the monitoring of mobile machines, maintenance and the procurement of spare parts. AR glasses also began to be used to facilitate maintenance.
• In 2021, the first Pipe Sizer was presented, a pipe processing machine with integrated laser inner diameter and ovality measurement, enabling ultra-precise measurement and sizing.

• In 2025, Dango & Dienenthal supplied the Pipe Sizer for bent pipes with predictive maintenance for the first time.

Contribution to industrialization

Dango & Dienenthal has significantly driven the development of the metal industry through the innovation and production of special machines. These include the following:

• Forging and transport manipulators: The company developed the first mobile forging manipulators in the 1930s. These machines revolutionized forging work by enabling the transport and precise handling of heavy, hot workpieces (forgings) on presses and hammers. The automation of these processes increased productivity, reduced physical demands upon workers and improved safety. Today, Dango & Dienenthal is a globally leading manufacturer in this sector.
• Equipment for blast furnace operations: At the start of the 20th century, the company specialized in the production of taphole closing machines and other equipment for blast furnaces, which are vitally important for the production of pig iron.
• Filter technology: Since the 1940s, Dango & Dienenthal has also manufactured cooling water filters, essential products for the operation and efficiency of production plants in the metallurgical industry.

Through the development of specialist equipment, the company has contributed to improving efficiency, automation and quality assurance in German steel and metal production. The company has grown from a regional enterprise in Siegen to a globally active company that has left a permanent mark on the sector as a result of its technological solutions and innovations.

Corporate structure

The D&D Group comprises several subsidiaries and brands that specialize in different sectors, including filter technology, heavy machine construction and technologies for the metal industry.

The company's core competencies are in the design and manufacturing of handling solutions, forging manipulators, ring rolling plants and systems for the metal production liquid phase.

Brands

The Group has several brands, including Dango & Dienenthal Maschinenbau, Dango & Dienenthal Filtertechnik, Hencon and TMT Tapping Measuring Technology.

Dango & Dienenthal Maschinenbau GmbH produces special machines and plants for the metallurgical industry. It specializes in the melting, forging, rolling, bending and heat treatment of metals. In addition, the company is a market leader in high-performance filter systems. It also offers contract manufacturing services.

Dango & Dienenthal Filtertechnik GmbH develops and produces filter systems for liquids that are used in almost all industrial branches. Its systems are designed to ensure fault-free operations around the clock, filtering river water, cooling water, process water (page in German) and other liquid media. The product range includes automatic and manual filter systems and separators such as the "Mussel Stop" system for the prevention of mussel larvae (particularly zebra mussels) in the cooling systems of industrial plants.

Hencon B.V., which has belonged to the D&D Group since 2015, focuses on the development, production and maintenance of special mobile appliances for the aluminum, mining and forestry industries.

TMT Tapping Measuring Technology GmbH, a joint enterprise of Dango & Dienenthal and Paul Wurth, manufactures tapping and measurement technology for blast and melting furnaces in the metallurgical industry. It offers products and services in the taphole and measurement technology sectors for blast furnaces and non-ferrous metallurgy. This includes the development, production, sales and maintenance of taphole machines and probes.

Products and services

Machines for the metal industry

• Melting: Plants for melting metals
• Forging: Machines for shaping metals through forging
• Rolling: Rolling machines for various metal products
• Bending: Machines for bending sheet metal and pipes, including induction benders
• Heat treatment: Heat treatment plants for metals
• Furnace tending machines: For material transport and charging furnaces
• Skimming machines: For removing slag from steelworks
• Handling systems: For handling metal products during production, including mobile transport manipulators
• Tongs: For handling forgings
• Forging manipulators: For the automation of forging processes

Filter technology

• Backwash drum filters: For the filtration of cooling water, process water, oils and other liquids
• Automatic filters: For the automatic filtration of various liquids including wastewater from sintering plants and descaling water as well as water infested with mussel larvae
• Plate filters: For the filtration of liquids in industrial applications
• Separators: For the separation of liquids such as cooling water, river water, seawater and oils

Services

• Custom machine solutions: Tailored plants for specific customer requirements
• Plant modernization: Updating and optimizing existing plants
• Measurement technology: Partnerships in the pipe inner measurement sector
• Advice and support: Support in selecting and using products

Commitments

The company takes part in local industrial and trade associations. The company's motto, "Better Values", reflects its self-proclaimed commitment "not only to the high quality of our products but also to our social and sustainable behavior" as well as its active dialog with the local public at all of the company's sites and the involvement of employees in decision-making processes. Since 2007, Dango & Dienenthal has been a member and supporter of the Forging Industry Association.

References

The corporate history is based on extracts from Steffen Platte's 150 Jahre Dango & Dienenthal ("150 Years of Dango & Dienenthal"), published by Dango & Dienenthal, Siegen/Hachenburg 2015; the Bibliographie zur Siegener Stadtgeschichte ("Siegen City History Bibliography") of the Siegen City Archives, and the official corporate history of Dango & Dienenthal.

External links

• Dango & Dienenthal
• D&D Filter Technology
• TMT - Tapping Measuring Technology

This article "Dango & Dienenthal" is from Wikipedia. The list of its authors can be seen in its historical and/or the page Edithistory:Dango & Dienenthal. Articles copied from Draft Namespace on Wikipedia could be seen on the Draft Namespace of Wikipedia and not main one.

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