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KSF – more than just history

Kommutatoren und Schleifringkörper

Kommutatoren & Schleifringkörper Finsterwalde GmbH (KSF) has been your reliable partner in the development and manufacture of commutators and slip ring assemblies in molded material for more than 60 years.

We owe our high quality standard to an extensive system of quality assurance measures. It is aligned and certified according to the requirements of DIN ISO 9001: 2015.

About us

Commutators and slip ring bodies from Finsterwalde have been used in rotating electric machines for more than 6 decades. During the privatization, in 1994, “Fimag-Kollektorbau” gave rise to KSF Kommutatoren und Schleifringkörper Finsterwalde GmbH.  Since then, our products have been developed, produced and sold under the KSF logo. Today, KSF GmbH stands as a reliable partner for more than 300 customers in Germany, Europe and overseas. The range includes over 2000 types in diameters from 7 to 395 mm. The produced quantities range from custom-made items for the repair sector up to large-volume series for the areas of household appliances and power tools.

From the smallest commutators for dental drills to collectors for truck and train drives to the slip ring bodies for wind power plants; in trusting co-operation with our customers, we find the right solutions. A special market advantage of KSF is its high level of production flexibility, which in addition to a large pool of special tools and equipment, can also be traced back to the maintenance of a large manufacturing depth. In this way, all essential components, including the bar profiles can be manufactured in-house.

New developments

Our company develops Hochleistungskommutatoren that for use at high mechanical loads – are suitable – up to 55 m / s circumferential speeds.

The development and introduction to market was supported by the Federal Ministry for the Economy and Energy based on a decision of the German parliament.

History of our company


Development and production of the first commutators and slip ring bodies in the FIMAG group. Commutators and slip ring bodies were manufactured for motors for the vehicle, agricultural and household appliance industries and for electric tools. The sizes of the components ranged from the DC drive for model railways up to those for mining equipment. During this time, approximately 8 million commutators and slip ring bodies were produced in Finsterwalde every year.


Private securitization and demerger from the FIMAG group and the renaming as “KSF Kommutatoren und Schleifringkörper Finsterwalde GmbH”. Internationalization of the market. Gradual specialization in the production of medium-sized and large commutators and slip ring bodies. Noteworthy in this period is the development and production of commutators and slip ring bodies for wind power generators and the expansion of our repair sector for assembled slip ring bodies.


Sale of KSF as part of the age-related transfer to the current owner.

2019 / 2020

In 2019, KSF started building a solar system on the roofs of the production facility with a total area of 4500 m². This is KSF’s largest single investment in years, amounting to EUR 750,000. The system went into operation in January 2020. In doing so, our company assumes its ecological responsibility. This system covers the majority of our own electricity consumption.


KSF Kommutatoren und Schleifringkörper Finsterwalde GmbH is an internationally respected manufacturer of commutators and slip ring bodies, which is able to offer its customers specific solutions, both for custom-made items and for medium-sized and large series. At 4000 m², KSF has an extensive machine park as well as a large pool of tool sets. The ability to deliver motor armatures, shafts, magnets and magnetic shoes rounds off the KSF profile.

Our development department, which is coupled to a separate toolmaking shop, is able to quickly and individually engage with customer requirements. Our quality management system is certified in accordance with ISO 9001: 2015 and guarantees our customers quality and satisfaction, not least as a result of extensive special test technology. The basic pillar of our success, however, is the commitment of all our employees, which results from a good social climate and consistent compliance with the requirements regarding occupational, health and environmental protection.