What Is White Graphite? The Complete Guide to hBN Hexagonal Boron Nitride Lubricant Additive

When a lubricant formulator needs a solid lubricant that does not darken a formulation, hexagonal Boron Nitride (hBN) is an important option. Nicknamed “White Graphite,” hBN combines a white appearance with electrical insulation, chemical inertness, and high-temperature stability.

This guide explains what hBN is, why its combination of properties matters, and how particle size and product form affect lubricant formulation choices.

What Is Hexagonal Boron Nitride (hBN)?

Hexagonal Boron Nitride (hBN, CAS 10043-11-5) is a synthetic inorganic compound with the chemical formula BN. It has a layered hexagonal crystal structure in which boron and nitrogen atoms are arranged in flat hexagonal lattices.

Weak interactions between adjacent layers allow them to shear relative to each other, which contributes to hBN’s solid-lubricant behavior.

hBN is typically produced through high-temperature synthesis from boron- and nitrogen-containing precursor materials.

Powderful Solutions supplies hBN as dry Solidex™ powders and as pre-dispersed Lubricore™ concentrates in synthetic-oil and ester carriers.

Why Is It Called “White Graphite”?

The name “White Graphite” comes from the structural similarity between hBN and graphite. Both materials have layered hexagonal structures and can exhibit lubricating behavior through interlayer shear.

The major practical difference is appearance: graphite is black, while hBN is white. This can be important in light-colored greases, coatings, polymers, and other formulations where dark solid lubricants would affect appearance.

hBN is also electrically insulating, whereas graphite is electrically conductive. This makes hBN particularly interesting where lubricant color or electrical properties matter.

Key Properties of hBN

*Values depend on grade, environment, test method, particle morphology, and formulation. Use product-specific technical data for design decisions.

hBN vs Graphite as a Solid Lubricant

Graphite and hBN share layered structural characteristics, but their practical behavior differs in several ways that matter to lubricant formulators:

• Temperature: hBN offers strong oxidation resistance at elevated temperatures in air.
• Electrical properties: hBN is electrically insulating; graphite is electrically conductive.
• Color: hBN is white, while graphite is black.
• Chemical behavior: hBN offers high chemical inertness in many lubricant and process environments.
• Lubrication: both materials have layered structures, but friction behavior depends strongly on atmosphere, surface condition, load, speed, and formulation.

For applications where electrical insulation, white color, or elevated-temperature stability are important, hBN can provide advantages over graphite.

hBN vs MoS₂ in Lubrication

MoS₂ and hBN are both layered solid lubricants, but they are typically selected for different formulation requirements.

MoS₂ is often selected where very low friction and high load-carrying performance under boundary lubrication are priorities. hBN becomes particularly interesting where white color, electrical insulation, chemical inertness, or elevated-temperature stability in air are important.

Rather than treating one material as universally better, formulators should select between hBN and MoS₂ based on operating temperature, atmosphere, load, color requirements, electrical requirements, base fluid, particle size, and contact conditions.

Primary Application Areas

• White and light-colored greases: where dark solid lubricants would affect appearance.
• High-temperature lubrication: oven conveyors, furnace components, glass processing, and similar elevated-temperature environments.
• Electrically sensitive applications: where an electrically insulating solid additive is advantageous.
• Clean industrial formulations: where white color and chemical inertness are desirable.
• Release agents and process lubricants: including high-temperature metal forming, glass processing, and mold-release applications.
• Polymer and composite systems: where hBN can provide lubrication, thermal-management, and electrical-insulation functions.

Particle Size Guide for hBN

Fine / Sub-Micron hBN Grades

Solidex B004 and Lubricore B230/B250 are fine hBN grades intended for lubricant formulations where dispersion, suspension stability, and fine surface coverage are important.

2.5 µm hBN Grades

Solidex B025 and Lubricore B260 are micron-scale hBN options suited to applications where particle geometry, surface coverage, or substrate roughness favor a larger particle size.

Modified hBN

Solidex B004M is a surface-modified hBN grade designed to improve compatibility and dispersion behavior in selected lubricant or material systems.

Exact D50, D90, and nominal-size specifications should be taken from the current product TDS for final formulation decisions.

Powderful Solutions hBN Products

• Solidex™ B004 — Fine hBN dry powder for lubricant and material formulation.
• Solidex™ B025 — Approximately 2.5 µm hBN dry powder for coatings, release, and lubricant applications.
• Solidex™ B004M — Surface-modified fine hBN for improved dispersion compatibility.
• Lubricore™ B230 — Fine hBN pre-dispersed in PAO-6.
• Lubricore™ B250 — 25% hBN in a synthetic vegetable-ester carrier.
• Lubricore™ B260 — 25% hBN in a synthetic vegetable-ester carrier, D90 approximately 2.5 µm.

View the Powderful Solutions product range →

FAQ

Is hBN suitable for food-industry lubricant formulations?

hBN is chemically inert and can be considered for lubricant formulations where white color and high-temperature performance are desirable. Food-industry use depends on the regulatory status of the specific ingredient, carrier, and finished lubricant formulation. Contact Powderful Solutions for product-specific documentation.

Can hBN replace PTFE in grease?

hBN can be evaluated as a PFAS-free solid-lubricant option in formulations where PTFE would traditionally be considered. Performance is formulation- and application-dependent, so friction, wear, compatibility, and treat rate should be validated in the finished grease.

Does hBN conduct electricity?

No. Hexagonal boron nitride is an electrical insulator, which differentiates it from electrically conductive graphite and makes it useful in formulations where electrical insulation matters.

What is the difference between hBN and cubic boron nitride (cBN)?

Hexagonal BN (hBN) and cubic BN (cBN) are different crystalline forms of boron nitride. hBN has a layered structure associated with lubrication, whereas cBN is an extremely hard material widely used in abrasive and cutting applications. They are not interchangeable.