75 years of cutting-edge manufacturing

Präwest was founded by an aerospace industry expert, Mr. Heinz Hampel in Bremen, Germany in 1945. Due to the turbulent post-war period that led to government restraints on aircraft manufacturing, the company started operations with special machining applications for the tobacco industry. Two years later the company returned to the roots of its founder and concentrated its activities on the machining of aerospace parts.

Today, Präwest is a tier 1 supplier to major OEMs and comprises of three independent entities: PRÄWEST, specialised in machining of large, heavy-weight parts; PRAE-AERO founded in 2015, dedicated to mass production processing of smaller parts for the aerospace sector; and CHAMPION PRECISION, founded as a joint venture in 2017 in China for selected niche products. The Präwest group confidently meets new machining challenges with a state-of-the-art machine park with over 130 CNC machines and 24 robots.

Machining specialised aerospace parts such as blisks, blades, vane clusters, impellers or rings and discs are problematic for many manufacturers. The challenge lies primarily in the nature of the raw materials, Titanium alloys, Inconel, nickel and cobalt based alloys as well as stainless steels which are difficult to machine. These materials are also the ones that Präwest possesses highest expertise in machining. Consequently, when it comes to acquiring new customer projects, three elements influence the company’s decision: Applications in difficult to machine materials; applications with complex geometries; and applications with the ability to reach a certain level of automation. Dr. Benjamin O’Shea, managing director of Präwest, confirms: “If two out of the three criteria are fulfilled in the customer’s request, it is most probably an attractive project for us and a contract that we want to win.”

Cooperation with other industry professionals play a fundamental role for the company’s success. Mitsubishi Materials is one of the cutting tool suppliers Präwest has partnered with to improve production efficiency and optimise machining processes of parts such as vane clusters and blisks. It was 2014 when the iMX high feed head end mill series with exchangeable heads was introduced to Präwest by Wolfgang Schmidt, sales representative at MMC Hartmetall GmbH, the European Headquarters of Mitsubishi Materials, as the ideal solution for the machining of clusters. Mr. Hoppe remembers: “We were unsatisfied with the performance of the in-house tooling. Additionally, the machining strategy, which was mainly trochoidal milling, clearly didn’t live up to our expectations to machine the narrow channels within titanium vane clusters and be able to leave the minimum material for finishing. When the iMX series outperformed every other tested cutting tool, as well as optimising the overall machining process, we realised that this tool would soon be our first choice not only for the machining of the clusters but also for other applications with similar machining strategies and parameters.”

Mr. Schmidt says: “After analysing Präwest’s initial requirements, it became clear that the exchangeable heads of the iMX series would be ideal. Additionally, the wide range of different types of geometries and long reach shanks available meant that these tools could effectively and reliably machine the complex shapes and materials specified by Präwest’s engineers. The first diameters tested were the 10, 16 and 20 corner radius types and it was found they could machine very close to the final nett shape. This provided a time saving when compared to other solutions because there was no longer a semi-finishing step needed.”

Today, Präwest utilises the iMX series for the manufacture of vane clusters in four 5-axis CNC milling machines in four different stages, producing over 1000 clusters yearly.

Continued Cooperation  

The successful implementation of the iMX series strengthened the partnership between the two companies. With the recently founded solutions centre, MTEC Stuttgart (Mitsubishi Materials Technology & Education Centre), Mitsubishi Materials can now provide Präwest with an advanced facility for their cutting tests. One of the future projects is an application of a semi roughing pocket milling in a stainless steel component, with a tool overhang length up to 180 mm. Mr. Wahlers says: “It is the first time we trust a partner with a cutting trial. In the past, we relied on our own means and expertise, but our positive experience of the collaboration with Mitsubishi Materials brought the benefits of such a partnership to the forefront.

Synergies with financial benefits in the metalworking industry are not rare, but when it comes to building new partnerships, other values matter. Dr. O’Shea concludes:” Quality has always been one of Präwest’s fundamental principles over the past 75 years. The anticipated high quality is also reflected in the products and services of Mitsubishi Materials. Acting more as a cutting-edge technology partner rather than a purely sales focused company is what we value most in this partnership.”