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Our BSH Screw plugs

Reliable sealing of gases and liquids

Bilstein & Siekermann® manufactures screw plugs made of aluminium, steel and brass. They are used to seal openings reliably and are used in various industrial applications including the automotive, hydraulics, plant and mechanical engineering industries. These screw plugs also perform reliably in transmission and drive systems.

We manufacture the screw plugs in the BSH cold forming® process with appropriate reworking. Conventional machining as a turned component or the reworking of forged blanks is also an option for small and medium quantities as well as for prototypes, pre-production series, series starts, series runs and for spare part requirements.

Our screw plugs product range includes standard and standard-like parts that comply with German and international standards such as DIN, EN and ISO.

The good sealing properties of the screw plugs are due to their precise adherence to narrow tolerances and the use of metal or elastomeric sealing rings. The sealing effect of parts without heads, such as sealing plugs according to DIN 906, is achieved by suitable thread pre-coatings.

  • Component according to standard (DIN 906, 908, 910, 7604) and specific solutions
  • Sealing systems: BSH sealing-E®, BSH sealing-M® and BSH sealing-T
Cleaning BSH Clean®

BSH Clean®

For perfect component cleanliness

Over time, the lack of residual particles has become a real quality feature. BSH clean® ensures the technical cleanliness of the components. In light of this, we pursue a strategy that addresses both the upstream process and the production processes, which is why BSH has set up a laboratory for monitoring component cleanliness.

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Use cases

Extremely short screw plug: Pressing instead of turning is the solution

Extremely short screw plug: Pressing instead of turning is the solution

A customer wanted a very short 10 mm screw plug with an M 27 thread for a special application. As the available installation space was tight, an extremely short thread with just two thread turns and very narrow shape and positional tolerances had to be achieved. The force application was to be via an internal torx drive. From a technical and economic perspective, it was practically impossible to produce the screw as a turned part. nevertheless, BSH succeeded in producing the screw in series.

BSH Sealing-M®: Pre-assembly optimises operational processes

BSH Sealing-M®: Pre-assembly optimises operational processes

Bilstein & Siekermann® supplies screw plugs to an automobile manufacturer, who originally manually fitted a copper sealing ring to these screws before they were mounted in several places in the engine. Manual assembly on site proved to be highly prone to errors: Final inspections that were conducted several times a day showed that either the sealing ring was missing or two sealing rings had been inadvertently used, which led to considerable delays in production BSH sealing-M® solved this problem.

One product – many possibilities

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Our Sales Team

Our Sales Team

Applications development

Applications development

HR department

HR department


Bilstein & Siekermann GmbH + Co. KG
Industriestraße 1
D-54576 Hillesheim

Video conferencing

In light of the current situation, we will be happy to discuss your topics in a video conference. To arrange an appointment, please contact us and tell us what you would like to discuss at info(at) You will receive a link to the meeting by email.

We have won awards

Awards are a mark of quality. See for yourself!

  • German Brand Award 2019
  • Innovator des Jahres 2018
  • TOP 100 2017
  • Großer Preis der Mittelstandes
  • Beste Arbeitgeber Marke 2019
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