A data-first reference for engineers evaluating hexagonal boron nitride as a dry lubricant, release agent, and anti-stick coating. Reviewed against the MK-hBN-SP product SDS and brochure.
Temperature stability at a glance
Maximum service temperature by atmosphere — the single biggest reason engineers switch to hBN. Scale: 0–1800 °C.
hBN values: manufacturer product data (MK-hBN-SP brochure). PTFE / silicone / oil values: typical published limits — always confirm against the specific product’s TDS.
hBN powder vs paste vs coating vs aerosol spray
Most pages blur these together. They are four different products with different films, thicknesses, and data. Datasheet numbers from one form do not automatically apply to another.
| Form | What it is | Typical film | Best for | Trade-off | Which data applies |
|---|---|---|---|---|---|
| hBN POWDER | Raw hexagonal boron nitride particles | None (loose)burnished or compounded | Formulating, compounding, dry burnishing | No binder — nothing holds it to the surface | Bulk material data only — not film performance |
| hBN PASTE / SLURRY | High-solids hBN in a carrier, brushed or dipped | Thicktens–hundreds of µm | Foundry ladles, crucibles, heavy release duty | Slow to apply; overkill for tooling touch-ups | That paste’s own TDS at its stated thickness |
| hBN BULK COATING | Water/solvent-based paint applied by spray gun or brush | Medium–thickcontrolled by applicator | Large fixed surfaces, production coating lines | Needs equipment, mixing, and cleanup | Coating TDS at cured thickness and cure schedule |
| hBN AEROSOL SPRAY | Fine hBN in a fast-flash solvent carrier + propellant, from a can | Thin, uniformcarrier flashes off; hBN bonds as dry film | Molds, dies, weld fixtures, hard-to-reach areas, maintenance | Thin film — reapply under wear; flammable carrier during application | Aerosol product data only (e.g. MK-hBN-SP SDS/brochure) |
hBN property table
Tap a category to expand. Verified = manufacturer product data (MK-hBN-SP brochure/SDS). Literature = published hBN material data — condition-dependent, verify for your application.
Thermal behavior · 4 properties
| Property | Value / Range | Status | What it means in practice |
|---|---|---|---|
| Max temp — air | 1000 °C | Verified | Oxidation-limited ceiling; covers glass molds, weld fixtures, heat-treat tooling |
| Max temp — vacuum | 1400 °C | Verified | Vacuum furnace and sintering setups |
| Max temp — inert gas | 1800 °C | Verified | Highest ceiling under N₂/Ar blanketing |
| Thermal conduction / expansion | Conducts heat; low expansion | Verified | Dissipates heat and stays dimensionally stable through thermal cycling |
Electrical & surface behavior · 4 properties
| Property | Value / Range | Status | What it means in practice |
|---|---|---|---|
| Electrical conductivity | Insulator | Verified | Safe where graphite’s conductivity is a defect, not a feature |
| Dielectric constant | Low | Verified | Low electrical interaction as a surface film |
| Non-wetting | Yes — molten metal & glass | Verified | The release mechanism: melt beads up instead of bonding to tooling |
| Color / cleanliness | White film | Literature | No black transfer marks on parts, hands, or fixtures (vs graphite/MoS₂) |
Chemical behavior · 3 properties
| Property | Value / Range | Status | What it means in practice |
|---|---|---|---|
| Chemical inertness | Good | Verified | Resists attack from many molten metals, slags, and process chemicals |
| Carbon content | Zero (B + N only) | Literature | No carbon pickup in sintering / powder metallurgy — graphite’s key failure |
| Formulation exclusions | No fluorocarbons, no lead, not ozone-harmful | Verified | Cleaner declaration than many legacy release aerosols |
Tribological (friction & wear) behavior · 3 properties
| Property | Value / Range | Status | What it means in practice |
|---|---|---|---|
| Lubrication mechanism | Layered lamellar shear | Literature | “White graphite” structure — weakly bonded sheets slide over each other |
| Moisture dependence | None — works in dry & humid air | Literature | Unlike graphite, lubricity doesn’t collapse in dry or hot environments |
| Coefficient of friction | Condition-dependentno single number is honest | Literature | Published values vary widely with load, speed, film, atmosphere — test your case |
Where hBN sits among dry lubricants
30-second orientation. For the full breakdown, see the hBN vs Graphite, PTFE, MoS₂ & WS₂ comparison guide.
| Dry lubricant | Max temp (air, typ.) | Color | Electrical | Needs moisture? | Pick it when… |
|---|---|---|---|---|---|
| hBN spray | 1000 °C | White | Insulator | No | You need clean, insulating, carbon-free, high-temp release or lubrication |
| Graphite spray | High | Black | Conductive | Yes | Cost rules and black residue / conductivity / carbon are acceptable |
| MoS₂ spray | Moderate | Dark grey | Semi | No | Heavy sliding load or vacuum, below its oxidation limit in air |
| WS₂ coating | High | Dark grey | Semi | No | Very low friction under load and budget allows |
| PTFE spray | ≈260 °C | White/clear | Insulator | No | Lowest friction and non-stick at low-to-moderate temperatures |
Benefits vs limitations
✔ Where hBN spray earns its keep
- Glass & ceramic molds — non-wetting release at temperatures that destroy PTFE and silicone
- Die casting & metal forming — release plus corrosion inhibition on dies and tooling
- Welding & brazing — dry anti-spatter for nozzles and fixtures, no oily residue
- Sintering / powder metallurgy — sticking eliminated without carbon contamination
- Casting, extrusion, forging, stamping — high-temp protective release coatings
- Clean maintenance — dry film that won’t drip, migrate, or attract dust like oil or grease
✖ Where it isn’t the right tool
- Extreme-pressure sliding contacts — MoS₂ or WS₂ usually outperform a thin hBN film
- Where conductivity is required — hBN is an insulator; use graphite instead
- Food, pharma or medical contact — this product is not rated for it (see SDS notice below)
- Unprepared surfaces — poor surface prep is the #1 cause of film adhesion failure
- Permanent one-coat fixes — thin films wear; plan reapplication intervals
- Untested conditions — always validate under real load, speed, temperature and atmosphere
Frequently asked questions
Is hBN the same as “white graphite”?
Structurally similar, chemically different. Both are layered lattices that shear easily — the lubrication mechanism — but hBN is boron and nitrogen (zero carbon), white, electrically insulating, and it doesn’t need adsorbed moisture to lubricate the way graphite does.
What temperature can hBN spray handle?
Per the MK-hBN-SP product data: 1000 °C in air, 1400 °C in vacuum, and 1800 °C in inert gas. The air limit is set by oxidation, which is why the atmosphere matters as much as the temperature.
Is hBN spray electrically conductive?
No — the hBN film is an electrical insulator with a low dielectric constant. That’s a core advantage over graphite wherever a conductive residue would cause shorts or interference.
Can I use hBN powder datasheet values for the aerosol spray?
No. Powder, paste, bulk coating, and aerosol spray produce different films with different thickness, adhesion, and wear behavior. Use the aerosol product’s own SDS/TDS, and validate the film under your actual operating conditions before production use.
Does hBN spray work as a mold release agent?
Yes — the non-wetting film is the release mechanism. Typical uses include glass making (improves mold/die life), plastic and rubber molds, die casting, and high-temperature protective release coatings.
How is hBN spray applied?
Onto a clean, dry, prepared surface in thin, even passes; the solvent carrier flashes off and the hBN bonds as a dry film. Surface preparation quality is the biggest single factor in adhesion. Reapply based on wear — thin films are consumable by design.
Evaluate hBN spray for your application
Get the TDS and SDS, order a trial can (single, box of 12, or carton of 48), or talk to a Lowerfriction specialist about your temperature, substrate, and release requirements.
Sources: MK-hBN-SP product brochure and Safety Data Sheet (M K Impex Corp. / Lowerfriction Lubricants); published hexagonal boron nitride materials literature for items tagged “Literature” — values are condition-dependent and should be verified for each application. Exporting from Mississauga, Canada to 50+ countries since 2004.