Text block

What is Hexagonal Boron Nitride (hBN)?

Properties & Industrial Applications

3 minutes

Originally published January 14, 2019. Updated May 16, 2025.

 

Saint-Gobain Boron Nitride Powder Solutions SP16

Hexagonal boron nitride (hBN), often known as 'white graphite', is a high-performance ceramic material used across a wide range of industrial applications. Its structure resembles that of graphite, yet its behavior is strikingly different, especially when exposed to high temperatures or electrical currents.

 

This article explains what makes hBN a material of choice, the forms available, its applications, and how Saint-Gobain’s boron nitride solutions excel in performance and reliability.

Key Properties of Hexagonal Boron Nitride

hBN offers a unique combination of functional traits, making it highly versatile:

  • High thermal conductivity
  • Electrical insulation
  • Thermal shock resistance
  • Dry lubricity for high-friction applications
  • Chemical inertness
  • Non-wettability against molten metals

Saint-Gobain enhances these natural properties through engineered grades featuring exceptional purity, oxidation resistance above 900°C, and optimized moisture control for long-term shelf stability.

Engineered to Perform

In practical terms, this means that Saint-Gobain’s hBN products perform reliably in mission-critical operations from satellite thrusters to furnace insulators and crucibles. The material’s combination of dielectric strength and thermal conductivity make it indispensable where conventional ceramics fail. 

Available Forms of hBN

Saint-Gobain offers hexagonal boron nitride in multiple engineered formats to support the unique needs of diverse industries and application environments. Each form is designed to deliver optimal performance based on how the material is processed or applied:

  • hBN Powders – Finely tuned for use in thermal pastes, cosmetic formulations, and industrial lubricants, these powders offer excellent performance and chemical purity. Available in platelet form or engineered agglomerates.
  • COMBAT® Machinable BN Ceramics – Hot pressed binder-bonded or composite ceramics that are easily machinable. These solids can be precisely shaped into high-temperature components such as crucibles, insulators, and custom fixtures.
  • CeraGlide® BN Coatings – Available in sprayable and paintable formats, ideal for protecting dies, molds, and contact surfaces from heat and chemical attack.

This versatility enables manufacturers, engineers, and designers to select the right hBN form for thermal protection, electrical insulation, or processing efficiency without compromising on quality or consistency.

Applications Across Industries

Thanks to its wide property set including thermal stability, chemical inertness, and dielectric strength, hexagonal boron nitride has become a preferred material across multiple industries. Saint-Gobain's hBN grades are actively used in:

  • Metal Forming – As a die release agent and anti-stick coating, hBN prevents metal adhesion in forging, extrusion, and casting. It is particularly well suited for aluminum casting and steel casting.
  • Electronics – For thermal interface materials and electrical insulation in circuit assemblies and LED systems.
    Aerospace – In satellite propulsion as an insulating chamber and hypersonics as electromagnetically transparent shields for electronics.
  • Semiconductors – In diffusion sources and high-temperature insulators.
    Lubricants – Incorporated into oils, greases, and pastes for lubrication under extreme pressure.

Whether the goal is to improve tool life, control thermal flow, or increase part precision, Saint-Gobain's hBN solutions are engineered to enhance your process or product.

Why Choose Saint-Gobain's Boron Nitride?

While hBN may be available from various suppliers, Saint-Gobain offers a unique advantage: reliable performance backed by over five decades of ceramic innovation. Our powders are of the highest purity and available in a wide range of particle sizes and shapes. Our coatings exhibit excellent adhesion and surface coverage. Every product is engineered for consistency, built for performance, and trusted across industries.
 

  • Frequently Asked Questions

    • What is the difference between hexagonal boron nitride and cubic boron nitride?

      In simple terms, hexagonal boron nitride, hBN, is very similar to graphite. It is the most stable and soft among BN polymorphs, and is therefore used as a filler, lubricant and an additive to cosmetic products. The cubic boron nitride, cBN, has similar crystal structure as diamond, and is the second- hardest known material after diamond. 

      We do not supply cBN within Saint-Gobain Boron Nitride.

    • What is the benefit of using different particle shapes, such as platelets or sphericals?

      Platelets tend to align in the direction of resin flow, and due to its inherent anisotropy, offer a very good in-plane thermal conductivity.  Platelets also allow for the addition of BN to systems that require a very thin layer or bond line that would be too big to allow agglomerates to be added. 

      Agglomerate grades - where small BN platelets are randomly oriented in all directions, like a snowball - overcome this limitation making BN an isotropic filler suitable for in-plane as well as through-plane thermal conductivity improvements.  Spherical Agglomerates (SA grades) are our most our most popular, and have the benefit of high flowability, packing, and tight particle size distribution. 

      LEARN MORE

    • Do you have recommended application guidelines for applying CeraGlide BN coatings?

      Yes, our CeraGlide Best Practices bulletin outlines recommendations for applying our coatings in detail. Whether spraying, brushing, or dipping, it is common practice to conduct trials with your specific substrate and application method to find the best conditions. Preheating the substrate to 100-200°F can help improve adhesion and reduce drying times for all coating grades. Once the coating is dry and has reached the desired thickness (we recommend building up layers with approx. 0.001" thickness), the coating is ready to use - no bake-out is required.

       

    • Are boron nitride machinable ceramics anisotropic?

      The pressing process to create a solid BN block induces some alignment of BN platelets in the process.  This creates properties of the material that can vary based on the orientation of that part relative to the pressing direction.  The difference in values of several properties in parallel and perpendicular to the pressing direction can be noted in the technical data sheet on the product page.

      Learn more on directionality of boron nitride machinable ceramics.

  • Conclusion

    Hexagonal boron nitride is more than a ceramic—it’s a multi-functional material engineered for modern manufacturing. From protective coatings to heat-resistant insulators, hBN stands at the intersection of performance and innovation. Explore Saint-Gobain’s full line of boron nitride solutions and discover how we can support your high-performance application.

     

     

  • Interested to learn more or ask specific questions?