EN 3924:1998

Overview - EN 3924:1998 (SIST EN 3924:2001)

EN 3924:1998 is a CEN aerospace series standard that specifies requirements for the nickel base alloy NI‑B41203 (NiCr7Si5B3) used as a filler metal for brazing - in tape form. The standard defines the expected characteristics and quality criteria for this specific brazing product intended for high‑performance aerospace applications. It establishes a common reference for producers, users and regulators working with nickel‑based brazing tape.

Key topics and requirements

While the full standard text contains the authoritative details, EN 3924 typically addresses these technical topics for the NiCr7Si5B3 brazing tape:

• Material identification and designation (alloy name NI‑B41203 / NiCr7Si5B3).
• Product form: specifications for filler metal supplied as tape.
• Chemical and metallurgical requirements: compositional constraints and alloy classification (as referenced by the alloy designation).
• Physical properties and usability: intended melting/flow behaviour and suitability for brazing nickel‑base substrates (general performance expectations).
• Manufacturing tolerances and dimensions: tape width, thickness ranges and acceptable deviations.
• Inspection and quality control: acceptance criteria, sampling and non‑destructive checks to ensure consistent product quality.
• Marking, labelling and packaging: traceability, identification and packaging practices suitable for aerospace supply chains. Note: For exact numeric limits, testing procedures and tolerances consult the official EN 3924 standard document.

Practical applications

NiCr7Si5B3 brazing tape covered by EN 3924 is used where durable, high‑temperature joints are required, especially in aerospace contexts:

• Repair and assembly of gas turbine components, combustors and heat‑exposed parts.
• Joining nickel‑base superalloys and high‑temperature steels in engines and hot‑section assemblies.
• Fabrication and refurbishment of aerospace heat exchangers, ducts and structural elements requiring controlled brazed seams. Because it is a nickel‑based filler, this tape is chosen for good oxidation resistance and compatibility with high‑temperature substrates.

Who uses this standard

• Aerospace OEMs and Tier‑1 suppliers specifying brazing materials.
• Filler‑metal manufacturers and brazing consumable distributors.
• Quality assurance, inspection and procurement teams in aviation and space industries.
• Repair, overhaul and maintenance (MRO) facilities performing brazing operations on engine and hot‑section components.

Related standards

EN 3924 complements other aerospace material and brazing standards, including specifications for brazing processes, brazed joint testing and general nickel‑base alloy classifications. Refer to CEN and national standards bodies for cross‑references and process qualification standards.

Keywords: EN 3924, NiCr7Si5B3, NI‑B41203, filler metal for brazing, brazing tape, nickel base alloy, aerospace brazing, CEN standard.