SIST EN 3939:2001

Overview

EN 3939:2001 (SIST EN 3939:2001) is a CEN aerospace standard that covers the nickel‑base filler metal designated NI‑B46001 (NiCo20Si5B3) in powder or paste form for brazing. The document specifies the requirements and intended use of this filler metal for aerospace applications, and is classified under non‑ferrous alloys (ICS 49.025.15).

Key topics and requirements

The standard focuses on requirements relevant to aerospace brazing consumables, including:

• Alloy designation and identification: NI‑B46001 (NiCo20Si5B3) as the reference filler metal.
• Product forms: acceptance criteria for powder and paste presentations suitable for brazing processes.
• Quality and conformity expectations: manufacturing, handling and supply conditions ensuring consistent performance for aerospace use.
• Packaging and marking to support traceability and safe storage/use in aerospace production and maintenance environments.
• Intended application domain and compatibility guidance for use as a filler metal in brazed joints subject to aerospace operating conditions.

Note: EN 3939 sets the framework and requirements for this filler metal; for detailed test methods, acceptance limits or process parameters, refer to the specific test standards and manufacturer data sheets referenced by the standard.

Applications

EN 3939 applies wherever a high‑reliability nickel‑base filler metal is required in aerospace brazing, for example:

• Repair and assembly of gas turbine components, heat exchangers and high‑temperature ducting
• Brazing of dissimilar materials in aircraft and engine subassemblies
• Production and maintenance tasks where powdered or paste filler metals are preferred for precision application

Using a standardized filler metal like NI‑B46001 helps ensure repeatable joint performance, traceability and compliance with aerospace quality systems.

Who uses this standard

• Aerospace OEMs and tier suppliers specifying brazing consumables
• Metallurgists and materials engineers selecting filler metals for high‑temperature service
• Quality assurance and procurement teams verifying supplier conformity
• Repair stations and maintenance engineers performing brazing repairs

Related standards

• Other EN/CEN standards on brazing and filler metals and national adoptions (e.g., SIST EN) that provide test methods, qualification procedures and complementary requirements for aerospace brazing processes.

Keywords: EN 3939, NI‑B46001, NiCo20Si5B3, filler metal for brazing, nickel base alloy, aerospace brazing, powder brazing paste, CEN, SIST EN 3939:2001.