What is EN15048?

EN 15048 is a European harmonized standard that specifies requirements for non-preloaded structural bolting assemblies (bolts, screws, studs, and nuts) used in metal structures like buildings and bridges .

📄 Core Two-Part Structure

The standard is divided into two complementary parts:

· EN 15048-1: General Requirements
  · Function: Defines the fundamental specifications for the bolting assembly components, including material grades (carbon steel, alloy steel, stainless steel, aluminum), mechanical property classes, and thread sizes.
  · Key Detail: Only complete assemblies (bolt + nut) tested together as a lot can be CE marked. Individual components cannot.
· EN 15048-2: Fitness for Purpose
  · Function: Specifies the testing and evaluation procedures to ensure the assembled products are fit for their intended use in construction.

🏗️ Key Scope and Applications

Primary Use

· It covers assemblies designed for structural metallic works, such as steel and aluminum structures, where connections are subject to shear and/or tensile loads.

Materials and Sizes

· Materials: Carbon/alloy steel, austenitic stainless steel, aluminum/aluminum alloys.
· Typical Thread Sizes: M12 to M39 for steel structures; M5 to M39 for aluminum structures. Larger sizes may be used if all standard requirements are met.

⚠️ Important Limitations

· Not for Preloading: It is for non-preloaded (or "bearing type") connections. For preloaded high-strength bolting (like in critical slip-resistant joints), the EN14399 series applies.
· Not for Welding: Components according to this standard are not designed to be welded.
· Material Restrictions: Aluminum bolts and nuts are not for use in steel structures.
· Exclusions: Railway rail fasteners are not covered.

🔧 Practical Relevance: CE Marking

As a harmonized standard under the EU Construction Products Regulation, EN15048 provides the basis for CE marking. This indicates the bolting assembly conforms to essential health, safety, and performance requirements for the European market.

In short, if you are sourcing, manufacturing, or specifying bolted connections for structural steelwork in Europe that do not require preloading, EN15048 is the key standard defining product compliance.

I hope this overview is helpful. If you are working on a specific project type, such as a steel frame building, I can try to provide more context on how this standard is applied.