About us

Strategic corporate group RM Industries

The Metallgiesserei Ralf Mewes GmbH (RM Guss) has been part of a strategic foundry group with Gestaguss-GEW Edelstahlgießerei GmbH since 1 September 2007.

We produce and supply a wide range of foundry products and accessories from a single source.

Whether aluminium chill casting, zinc chill casting system components, grey, malleable, stainless steel or steel casting, manganese hard steel or wear casting, we are your partner for quality casting “Made in Germany”. Today, the RM Industries group of companies produces at 4 locations on an area of over 100,000 square metres.






Ralf Mewes

Born: 1966
Managing partner

Self-employed since 1986 and founder of Metallgiesserei Ralf Mewes GmbH. (RM Guss) Starting out in a double garage, the managing director is still a good counsellor for the next generation with ideas and foresight to break new ground in a traditional trade.

Kevin Ralf Mewes

Born: 1989
Managing partner

Kevin Mewes completed his apprenticeship in a third-party metalworking company before joining the family business RM Guss in 2009, where he worked in all departments until the junior KM joined the second-generation management team in 2014. Today, he is responsible for the company’s fortunes and the growth of the sites.

Hiostory of the Metallgießerei Ralf Mewes GmbH

Synonym for quality work from a special mould

Foundation of  Metallgießerei Ralf Mewes GmbH

At the age of 20, Ralf Mewes set up his own business on 1 February 1986. In 1987, Metallgiesserei Ralf Mewes was founded, which was then transformed into Metallgiesserei Ralf Mewes GmbH in 1996. The company initially only dealt with aluminium chill casting and its processing. It expanded continuously. In 1991, Ralf Mewes (RM) took over the production of the Nettelbeck/Ostermann foundry. With this transaction, the company grew very rapidly, so that RM bought a plot of 5,950 square metres in the Röbeck industrial estate in 1995. This plot was then developed in 1997 with a hall and office wing with a total area of 3,850 square metres. In the meantime, the company had become an integral part of the industry as a full-service provider of toolmaking, foundry, mechanical processing and finished system components. In 2002, another toolmaking shop and a high-bay warehouse were added, increasing the production area to around 5,000 square metres. Over the following years, several small foundries were taken over. In 2015, the production and property of Grundscheid GmbH was taken over and renovated on an area of 8,500 square metres, our current Plant 2, which houses the warehouse and a state-of-the-art CNC machining facility with 3-, 4- and 5-axis machines.

Since 2009, the next generation has also been established in the RM Group with Kevin Mewes, who became a partner and joined the management board in 2014, setting the course for the coming decades.

1. new building of the Metallgießerei Ralf Mewes GmbH

The management is responsible for consulting, development and design through to the final product. Our range of services is not limited to aluminium casting. We are also happy to be your contact for brass and zinc castings as well as metal goods. With our modern foundry, in-house tool and mould making, machining options on 3-5 axis CNC machines and 4-axis pallet changing machining centres, we currently machine your castings or components on 12 machining centres. With a wide range of expertise in system component assembly, we meet the challenges of our customers today.

Our company was one of the first aluminium foundries to be certified to DIN EN ISO 9001 back in 1996. On 21 February 2003, we were re-certified by AEROCERT in accordance with DIN EN ISO 9001:2000, a clear sign that quality is the be-all and end-all of our company philosophy. In order to meet the increasing demands of the times, we moved into a spacious new building in 1997. 3,000 square metres of production space, expanded to 5,000 square metres at the beginning of 2001, and a modern machine park provide the ideal conditions for remaining on the road to success. Today we have a production area of 12,500 square metres at our disposal.

Extension Factory 1 Metallgießerei Ralf Mewes GmbH

Today, we produce around 80 tonnes of aluminium gravity die castings per month. After all, this material of the future has a number of convincing advantages: In addition to its low weight, high ductility, good thermal and electrical conductivity, high weight/strength ratio, wide range of finishing options and excellent corrosion resistance, it is also its incomparable recyclability and attractive price/performance ratio that speak in favour of using aluminium.

However, it is not only technical expertise in the field of aluminium, stainless steel and cast iron that sets us apart, but also the partnership-based cooperation with our customers. Around 1200 companies from a wide range of industries, including mechanical engineering, the automotive industry, the furniture industry, sun protection technology, the construction industry, the stone and earth industry and medical technology, rely on the quality work of Ralf Mewes GmbH.

Rebuilding Fatory 2 in the Haberstraße 8 – 10 in Velbert (NRW)

In 2015, we took over the property, machines and customer base of Grundscheid and rebuilt our current Plant 2, which houses a state-of-the-art CNC machining centre, assembly and warehouse. Thanks to large reserves in the total area, further growth in the group is assured.
Well-known companies such as MAN, Siemens and Daimler are among our regular customers. Our success as a casting supplier is reflected in figures not only in Germany, but throughout Europe and worldwide: we realise 12-15 percent of our annual turnover in other European countries. Germany’s neighbouring countries Austria and Switzerland play a major role in this.

Acquisition of  Gestaguss GEW in Velbert

Acquisition of  Gestaguss GEW in Wetterzeube

The Gestaguss foundry group was acquired on 1 September 2007. With around 65,000 square metres of operating space, it was the largest acquisition in the company’s history. This purchase consisted of an iron foundry established in the 1960s with an operating area of around 20,000 square metres where grey cast iron, chilled cast iron and malleable cast iron were produced. Today’s GEW Guss GmbH is the last iron foundry of its kind in the Mettmann district, out of the 65 foundries in Velbert. It also includes Gestaguss GEW Edelstahlgießerei GmbH in Wetterzeube (Saxony-Anhalt) with a production area of around 45,000 square metres. This production facility, which celebrated its 100th anniversary in 2009, produces steel and stainless steel castings in over 200 different alloys. Today, Gestaguss GEW produces around 1,000 tonnes of steel and stainless steel, as well as approx. 1,000 tonnes of grey cast iron, malleable cast iron and chilled cast iron.

Castings are supplied to all conceivable branches of industry at all locations.

New administration building in Wetterzeube


DIN EN ISO 9001:2015

Scope of application:
Development and production of aluminium castings, system components, moulds and tools,
CNC machining

DIN EN ISO 50001:2011

Scope of application: Development, production & distribution of aluminium castings, system components, moulds and tools; CNC machining