The stainless steel specialist

As one of the leading manufacturers 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 exacting requirements, and stainless steel A8 is used where there are extended high-corrosion (HCR) requirements. These stainless steels are optimally suited for outdoor use.


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

Fastening classification
in acc. with ISO 3506-6, 
2020-04 edition

Meaninglowmoderatemediumstrongvery strong
A2 1.4301
A3 1.4541   
A4  1.4401
A5  1.45711.4539 
A8    1.4529

Stainless steel A2/A4

Connection elements made of stainless steel A4 have the advantage that they are relatively resistant to salt water and acids. Typical areas of use for screws made of stainless steel A4 are in the immediate vicinity of salt water. Stainless steel A2 screws are unsuitable due to the high salt content of the water and air in these environments.


  • 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)
  • Resistant to salt water and acid (A4)

STAINLESS STEEL A5 1.4539/A8 1.4529

Stainless steel A5 and A8 are more highly resistant to corrosion and acid than stainless steel A2 or A4 (HCR).

Connection elements made of A5 are used in atmospheres containing chlorine, for example in indoor swimming pools or by the sea in direct splash water areas (jetties).

Applications for stainless steel A5

  • Load-bearing fastenings for ceiling and wall cladding
  • Shipbuilding
  • Medicine and pharmaceuticals, chemistry, foodstuffs, agriculture and construction


  • 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 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.  

Applications for stainless steel A8

  • 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.


Julian Oppermann
Tel.: +49 7940 127-410