Proven expertise for more than 50 years

Tradition, flexibility and innovation: Independent, value-oriented action with a high level of vertical integration and in-house production ensures that we can always meet our high quality standards in a socially responsible manner.

Success through experience and knowledge

Renowned for long-lasting products: Our technical expertise and craftsmanship guarantee the long-term operational and functional safety of our products. The best proof: some of our machines have been doing their job reliably for over 40 years! For decades, SIEFER has also stood for

  • a competitive edge through individual technical solutions

  • innovation-driven focus on core expertise

  • with a partnership-based consulting approach

  • a consistently entrepreneurial, commercially sound, and socially responsible business conduct

Consolidated expertise in one place

Even in times of outsourcing, lean production and relocation abroad, we believe in the advantages of a high level of vertical integration with broad production expertise located directly at our German site. To meet our high standards at all times, we develop and manufacture our products exclusively in-house, and are constantly investing in the latest and most modern processing machines to maintain this advantage for the customer.

In special fields outside of our core areas of expertise, we work closely with carefully selected and established partners. This ensures that we always have a close relationship with our customers and vouch for our strong performance – today and tomorrow.


Machines sold
since 1978


Market share of
SIEFER Trigonal® machines


All machines ever produced
that are still in operation

State-of-the-art manufacturing
for the benefit of our customers.


With its Trigonal® brand, Wilhelm Siefer GmbH & Co. KG specialises in the development of mixing and size-reduction machines for processing products of low to high viscosity in the form of liquid mixtures or solids in liquids.