For the designer
You can safely specify a carbon steel screw for the project, knowing that the product meets the requirements for outdoor use and aligns with the objectives of the new Building Act.
ETA approval
Proven to be the only carbon steel roofing screw approved for outdoor use
Until 2025, painted carbon steel screws were sold for outdoor use without their actual corrosion resistance having been tested under demanding outdoor conditions or in corrosion tests.
KINGI® changed this at the beginning of 2026.
We are the world’s only painted carbon steel screw that has been genuinely tested and officially approved for the severe C4 atmospheric corrosivity category in accordance with the new ETA-25/0267 assessment.
A CE mark alone does not make a screw legal for outdoor use
Many boxes of carbon steel roofing screws on the market bear a CE mark.
However, this alone does not mean that the product is approved for long-term outdoor use.
The CE marking is not a quality mark or a guarantee of corrosion resistance.
In some cases, the marking may have been granted without actual corrosion tests corresponding to outdoor use.
Under the old assessment basis, fasteners approved for outdoor use were assumed to be made of stainless steel. Nevertheless, painted carbon steel screws were widely sold on the market for roof fastening.
In practice, this left the responsibility to:
- the developer
- the designer
- the contractor
KINGI® wanted to change the situation.
Only genuine corrosion tests prove durability
We did not want to build our products on assumptions.
That is why we require the outdoor use of carbon steel screws to be approved only for products whose corrosion resistance has been demonstrated through real tests.
A new European Assessment Document (EAD) was published as a result of this work, and for the first time it is based on genuinely tested corrosion resistance.
KINGI® is the first and so far the only painted carbon steel screw that:
- passed demanding corrosion tests
- received ETA approval in accordance with the new EAD
- was approved for the severe C4 atmospheric corrosivity category
By choosing KINGI®, you choose a fastener that genuinely meets modern outdoor use requirements.
What does this mean in practice?
For the contractor
You can show your customer that you use the only genuinely tested and approved painted carbon steel screw on the market.
For the building inspector
Inspection is easier and more transparent when an officially approved and identifiable fastener is used.
Download the ETA-25/0267 and Declaration of Performance (DoP) for Kingi screws
Explore the official documents, approval documents and technical information.
Download the Declarations of Performance (DoP) for the screws
Frequently asked terms
What is EAD?
European Assessment Document, i.e. the European assessment document on the basis of which the product’s performance is assessed.
What is the ETA?
European Technical Assessment, that is, a European technical assessment demonstrating the product’s approved intended use and performance.
What does the CE mark mean?
The CE mark indicates that the product meets the EU requirements specified for it. It alone does not prove the product’s long-term corrosion resistance in outdoor use.
What does the C4 atmospheric corrosivity category mean?
C4 is a corrosion exposure class in which the product is required to have very good corrosion resistance, for example in humid, coastal and industrial environments.
