IEC 60672-3:1997

Overview

IEC 60672-3:1997 - "Ceramic and glass‑insulating materials - Part 3: Specifications for individual materials" is an International Electrotechnical Commission (IEC) standard that gives a practical classification and typical numerical values for the major characteristics of ceramic, glass‑ceramic, glass‑mica and glass insulating materials used for electrical insulation. It is the third part of the IEC 60672 series (with Part 1: definitions/classification and Part 2: test methods) and presents guidance and minimum material specifications based on tests performed on specified specimens.

Key topics and technical requirements

The standard focuses on material classification and characteristic data rather than detailed test procedures (those are in IEC 60672-2). Key technical topics covered include:

• Material groups and subgroups (e.g., alumino‑silicate porcelains, steatites, titanates, high‑alumina ceramics, glass‑ceramics and glass types).
• Typical numerical values for major properties, such as:
  • Open (apparent) porosity and bulk density
  • Flexural strength (unglazed/glazed) and modulus of elasticity
  • Thermal properties: coefficient of linear thermal expansion, thermal conductivity, specific heat, resistance to thermal shock
  • Electrical properties: dielectric (electric) strength, withstand voltage, relative permittivity, temperature coefficient of permittivity, dissipation factor (tan δ), and volume resistivity (at various temperatures)
• Use of underlined/bold figures in the tables to indicate properties usually critical for application and forming the basis for minimum material specification.
• A clear note that tabulated values apply to specified test specimens and methods, and may not directly extend to finished components without additional evaluation.

Practical applications

IEC 60672-3 is used for specifying and comparing insulating materials for electrical applications where reliable dielectric and thermal performance is required. Typical practical applications include:

• Specification of materials for high‑voltage insulators, bushings and feedthroughs
• Selection of ceramic/glass materials for electrical components, substrates and insulating supports
• Material data reference during design reviews, procurement and failure analysis
• Input to material selection for manufacturing processes (metallization, glazing, firing)

Who should use this standard

• Electrical and materials engineers specifying insulating components
• Ceramic and glass material manufacturers and suppliers
• Component and equipment manufacturers (power, switchgear, transformers)
• Test laboratories and quality assurance teams
• Procurement and standards compliance specialists

Related standards

• IEC 60672‑1 - Definitions and classification
• IEC 60672‑2 - Methods of test

IEC 60672‑3:1997 provides authoritative, tabulated material characteristics that streamline material selection and specification for electrical insulation-useful as a baseline reference while ensuring final product specification is based on actual component requirements and testing.