IEC 60404-6:2018

Overview

IEC 60404-6:2018 - "Magnetic materials - Part 6" defines standardized methods for the measurement of AC magnetic properties of magnetically soft metallic and powder materials using ring specimens. The standard covers frequencies from 20 Hz to 100 kHz and applies to materials other than electrical steels and soft ferrites, including speciality alloys, amorphous and nano‑crystalline soft magnetic materials, pressed/sintered and metal‑injection‑moulded (MIM) parts, cast parts and magnetically soft composites. This edition updates measurement practice to modern instruments, incorporates digital sampling techniques, and adds a wattmeter method for determining specific total loss.

Key topics and technical requirements

• Scope and specimen preparation
  • Use of ring specimens; powder materials are formed into rings by appropriate pressing methods.
• Measurement methods
  • Voltmeter‑ammeter (conventional) method for permeability and AC magnetization curves.
  • Wattmeter method (Clause 7) for measurement of specific total loss.
  • Adoption and guidance for digital sampling techniques (informative Annex B) for acquisition and evaluation of measured waveforms.
• Measured quantities
  • Peak and r.m.s. magnetic flux density (B), magnetic field strength (H), relative amplitude permeability, AC magnetization curves, and specific total loss.
• Instrumental and procedural details
  • Requirements for windings, temperature measurement, waveform control, and methods to minimize additional losses (Annex A).
  • Calibration, uncertainty assessment and test reporting requirements.
• Notable changes in this edition
  • Formal limitation of frequency range to 100 kHz.
  • Removal of the digital impedance bridge clause and addition of practical digital sampling guidance.

Applications and users

• Who uses IEC 60404-6:
  • Material manufacturers and quality labs performing AC characterization of soft magnetic materials.
  • R&D engineers and testing laboratories assessing permeability, losses and magnetization behavior.
  • Component designers specifying materials for inductors, transformers, power‑electronics cores, EMI filters and magnetic composites.
  • Certification and QA teams needing standardized, traceable measurement methods.
• Practical value:
  • Provides reproducible, comparable data for material selection and performance prediction at frequencies relevant to modern electronics and power systems.
  • Enables consistent evaluation of losses and permeability across published material data sheets.

Related standards

• IEC 60404 series - general series on magnetic materials.
• IEC 60404-4 - ring method for DC magnetic properties.
• IEC 60404-8-6 / IEC 60404-8-9 - lists and specifications for speciality alloys and pressed/sintered/MIM parts.
• IEC 62044-3 - measurement of magnetic characteristics of magnetically soft components (high excitation levels).

Keywords: IEC 60404-6, magnetic materials, soft magnetic materials, ring specimens, AC magnetic properties, digital sampling, specific total loss, permeability, wattmeter method.