The production specialists

We’re experts here

  • Use of all materials that can be cold formed: Stainless steel in A2 / A4 / A5 / A8 quality, steel in different qualities and strengths, special materials, bi-metal, aluminium, brass and much more.
  • A wide variety of heat treatments, surface treatments and surface coatings, tempering to 8.8/10.9, case hardening, inductive hardening, tempering
  • Development of innovative products
  • Development and implementation according to your requirements
  • Customer-specific solutions from several components

Our machinery

  • Presses for cold forming
  • Thread-rolling machines
  • Welding systems for bi-metal screws
  • Welding systems for solar fasteners
  • Washer insertion machines
  • Inductive hardening systems
  • Annealing systems
  • Tempering ovens
  • Pinching machines

Production is the beating heart of our company. That’s because we believe in quality made in Germany as the basis for perfect connection solutions.

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How is a screw created

The screw blanks are pressed using the cold forming process. The corresponding head geometry is shaped on a wire section.

The pin blank is pressed using the cold forming process. The corresponding head geometry is shaped on a wire section. The phase geometry required for welding is also pressed on here.

The pin is welded to the screw blank using automatic resistance welders.

Here, the structure of the two welded halves is soft-annealed again to make further machining possible.

An uneven bead is formed during welding, which is levelled by calibrating between two smooth rolling jaws.

The drill geometry of the screw tip is pinched between two pinching tools moving towards each other.

In a separate thread rolling process, the underhead thread is first rolled under the screw head.

A second rolling process involves rolling on the main thread, which later ensures a firm hold in the substructure.

In this process, the structure in the steel part of the screw tip is hardened in order to obtain the hardness that the tip requires for drilling.

To ensure that the drill tip is not too hard and brittle, it is then heated to a red-hot temperature and slowly cooled down again.

A coating is applied to the surface of the screw to provide the necessary corrosion protection and improve its sliding properties.

The screw is fitted with a washer, which is pushed onto the screw mechanically or partly by hand

So that the products can be handled appropriately, they are packaged in certain batch sizes and labelled for identification.

Creation of a screw
Creation of a bi-metal screw

Small materials customer


Steel is a material consisting mainly of iron with a low carbon content, and a distinction is made between unalloyed (limited hardening properties) and alloyed steels (good hardening properties). Our steels are manufactured on the basis of our delivery specifications, which are based on DIN EN 10263-1 to -4 for cold-dip and cold extruded steels.

Stainless steel

Stainless steel has a high chromium content (min. 10.5 percent) and a carbon content of max. 1.2 percent. The chromium content forms a passive layer on the material surface that protects against corrosion and has a self-healing effect in the event of minor damage to the surface. 

Other alloy components include nickel and molybdenum. They increase corrosion resistance. We only use austenitic stainless steels (A2 to A5), these being the main structural component of many stainless steels and non-magnetic. We recommend working with stainless steel screws outdoors.


Our bi-metal screws consist of two metals ("´bi") that are firmly bonded together. Stainless steel and steel are welded to form an inseparable bond. The advantages of each metal can be used in these screws.


Our competence - stainless steel

As an industry specialist in the manufacture of stainless steel screws, we manufacture quality products made of A2, A4, A5 and A8 stainless steel in accordance with the standards applicable to the respective applications.

The most common types of stainless steel used in connection elements are A2 and A4. Stainless steel A5 is used for more stringent requirements and stainless steel A8 for requirements involving high corrosion resistance (CRC V in accordance with DIN EN 1993-1-4). 
These stainless steels are ideally suited for chlorinated and saline environments, whether indoors or outdoors.

Application areas & advantages


The advantage of A2 and A4 stainless steel connection elements over C1 stainless steels is that they possess better corrosion properties. A4 screws in particular are ideal for use in salt water or acidic environments, as they are highly resistant in both cases. Typical areas of use are in the immediate vicinity of salt water.

  • Connections indoors and outdoors and in damp rooms
  • Gardening and landscaping
  • Terrace construction and wood constructions

  • Corrosion-resistant against the effects of the weather (A2/A4)
  • Resistance to salt water and acids
    (A4, particularly tannic acid)


Stainless steel HCR 1.4539 is more resistant to corrosion and acids than A2 or A4 stainless steels. Connection elements made of HCR 1.4539 are used in atmospheres containing chlorine (for example indoor swimming baths) or by the sea where there is direct water splashing (jetties).

  • Load-bearing fastenings for ceiling and wall cladding
  • Shipbuilding
  • Medicine and the pharmaceuticals industry, chemicals industry, food and construction industries, agriculture

  • Good corrosion resistance to aggressive media such as phosphorus, sulphur and hydrochloric acid
  • High resistance to pitting and stress corrosion


The stainless steel A8 1.4529 is a further development of the material HCR 1.4539 and is characterised by its particularly high resistance (CRC V) to local corrosion phenomena such as chlorine-induced cracking, stress corrosion or pitting. In addition, it has good polishing and mechanical properties and can be used in a wide temperature range. This is why the material is mandatory in the specific areas for fastenings used on load-bearing components.

  • Atmospheres containing chlorine in indoor swimming baths and pool technology
  • Tunnel and multi-storey car park construction
  • Decorative purposes and kitchen equipment
  • Used in salt water or brackish water, offshore and shipbuilding technology

  • Particularly high resistance to chlorine-induced stress corrosion and pitting

The table below shows an overview of the most frequently used materials.

Corrosion resistance classes in accordance with DIN EN 1993-1-4: 2015-10 / Eurocode 3 Appendix A are mandatory for the selection of materials used in construction.


  Corrosion resistance classes (CRC) in accordance with DIN EN 1993-1-4: 2015-10          
Resistance classification in accordance with ISO 3506-6, Edition 2020-04 Category I II III IV V
  Meaning low moderate medium strong very strong
  A2   1.4301 1.4567      
  A3   1.4541      
  A4     1.4401 1.4578    
  A5     1.4571 1.4539  
  A8         1.4529

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