High-Temperature Grease: A B2B Sourcing Guide
A high-temperature grease is a lubricating grease engineered so its thickener structure, base oil, and additive package keep working — resisting oxidation, holding their consistency, and continuing to protect moving parts — at continuous operating temperatures that would break down a standard general-purpose grease. Before comparing products, buyers need to understand the single most common mistake in high-temperature grease selection: a grease's dropping point is not its maximum operating temperature, and treating the two as interchangeable can lead to a product failing well before its datasheet number would suggest. This guide explains what actually defines a high-temperature grease, how thickener chemistry and testing determine real service life at heat, and what to specify when requesting a quote from an export supplier.
What Is a High-Temperature Grease?
A high-temperature grease is defined by its actual rated continuous service temperature and oxidation life at heat — not by any single datasheet figure. There is no single global regulatory definition of the category; it is a catalog grouping built around a cluster of measurable properties: dropping point (the temperature at which the thickener structure collapses), oxidation stability under static heat, and dynamic running life in an actual bearing.
As a reference point, a general-purpose lithium NLGI 2 grease is typically rated to roughly 120–130°C continuous. High-temperature greases are specified wherever ambient heat plus friction pushes a component meaningfully above that ceiling: kiln-car and rotary-kiln bearings, oven-conveyor bearings, foundry and steel-mill equipment, exhaust-adjacent automotive and industrial bearings, electric-motor bearings running hot due to duty cycle, and paint-curing or drying-oven conveyors.
Does a Higher Dropping Point Mean a Grease Can Run Hotter?
No. Dropping point (tested to ASTM D2265) is a laboratory indicator of thickener heat resistance under specific, standardized test conditions. It is not a maximum-use-temperature rating, and the maximum continuous service temperature of a grease is always well below its dropping point.
This is the most commonly repeated error in grease selection, so it is worth stating plainly: a grease with a higher dropping-point number is not automatically usable at a higher operating temperature. The two figures measure different things.
Dropping point is a one-time, static structural failure point — the temperature at which the thickener's internal network breaks down and the grease liquefies, measured over a short standardized heating ramp. Maximum continuous service temperature is an engineering judgment about how long a grease keeps lubricating under real running conditions — resisting oxidation, retaining consistency, not bleeding oil, not hardening — over weeks, months, or years of load, speed, and air exposure. That judgment comes from separate dynamic tests (see "How Is High-Temperature Grease Performance Actually Tested?" below), not from the dropping-point figure.
A widely used industry rule of thumb — an engineering heuristic, not an ASTM-defined formula — puts the maximum continuous operating temperature roughly 50–100°C below the dropping point, though the exact gap depends on thickener chemistry and application. Treat this only as a buyer sanity check, never as a substitute for a supplier's own stated maximum continuous service temperature.
At the very top of the range, the relationship breaks down further: bentonite/clay-thickened greases have no conventional dropping point at all (they do not melt under ASTM D2265 conditions), and PTFE/PFPE-thickened products' real ceiling is governed by base-oil volatility and oxidation resistance rather than a soap-melt event. Trade sources report that above roughly 200°C dropping point, the dropping-point-to-service-temperature correlation effectively stops being a useful predictor — at that end of the range, ask the supplier for test data, not a dropping-point figure.
Buyer-facing rule: always request two numbers — the dropping point and the supplier's own stated maximum continuous service temperature, ideally backed by dynamic life-test data — and never select or compare high-temperature greases on dropping point alone.
What Thickener Systems Are Used in High-Temperature Greases?
Five thickener families dominate the high-temperature category, each with a different practical ceiling and a different trade-off. Use the table below as a starting reference only, and always confirm a specific product's dropping point and stated service temperature against its own technical data sheet.
| Thickener | Dropping Point (ASTM D2265) | Typical Max. Continuous Service Temp. | Key Trade-off |
|---|---|---|---|
| Lithium-complex | ≥250°C | ~150–180°C | Good all-round workhorse with moderate-to-good water resistance; incompatible with plain lithium soap and with polyurea |
| Calcium-sulfonate complex | >300°C | ~150–180°C, varies by formulation | Outstanding water/salt-spray resistance with inherent extreme-pressure performance; preferred where heat and water/corrosion apply together |
| Polyurea | >260°C | Supplier-specific; common in sealed-for-life electric-motor bearings | Very low oil bleed; incompatible with virtually all soap-based thickeners — mixing can cause catastrophic softening or hardening within hours |
| Bentonite/clay (non-melting) | No conventional dropping point — does not melt under ASTM D2265 | ~200°C+ | A heat-only specialist for kiln bearings and oven conveyors where soap-thickened greases would melt; typically weaker shear stability at lower temperatures |
| PTFE-thickened | Stable to roughly 260°C; some formulations to 204–302°C with a PFPE base | Application-specific | Not a soap — resists strong acids, caustics, halogens, and solvents; very low friction; typically reserved for chemical-processing and extreme-service duty on cost grounds |
Two synthetic base oils extend the usable range further, independent of thickener choice. PAO (polyalphaolefin) is a synthetic hydrocarbon that broadens both the low- and high-temperature range beyond mineral oil while remaining compatible with conventional thickener chemistry. PFPE (perfluoropolyether) is a fully fluorinated synthetic base oil, thermally stable to roughly 300°C and chemically inert to acids, solvents, and oxygen — used at the extreme top of the range in aerospace, semiconductor processing, high-vacuum, and similar niches. PFPE greases are almost always PTFE-thickened, since conventional soap thickeners are not compatible with a fluorinated base oil.
Mandatory compatibility note: different thickener families should never be mixed in the field without laboratory-confirmed compatibility, and this is especially critical for polyurea. Converting a bearing from one thickener family to another requires a full purge and regrease — never a top-up.
What Happens to Grease at High Temperature, and How Often Should It Be Reapplied?
Heat accelerates base-oil oxidation, and relubrication intervals must shorten substantially as operating temperature rises. As a directional engineering heuristic — not a fixed figure for every product — grease life is often described as roughly halving for every 10°C rise in operating temperature, reflecting the same Arrhenius-type oxidation principle used to model lubricant degradation generally. Always confirm the actual interval against the specific grease supplier's or the bearing manufacturer's guidance rather than applying this heuristic directly to a maintenance schedule.
Four mechanisms drive that degradation:
- Base-oil oxidation — reacts with atmospheric oxygen faster as temperature rises, forming acidic by-products, varnish, and eventually hardened deposits; the dominant heat-related failure mode for mineral- and most synthetic-base greases.
- Oil bleed/separation — some thickener systems bleed oil faster at elevated temperature, starving the bearing before the bulk grease visibly fails.
- Consistency drift — hardening (reduced flow into the contact) or softening (leakage, churning losses), depending on thickener chemistry and oxidation by-products.
- Volatilization — lighter base-oil fractions evaporate faster at heat, raising the apparent viscosity of what remains and eventually leaving a dry, non-lubricating residue.
The relubrication interval printed on a general-purpose grease's data sheet does not apply once a component runs meaningfully hotter than that grease's design point. Ask the supplier for a temperature-adjusted schedule, or for dynamic life-test data at a temperature close to the actual operating condition.
How Is High-Temperature Grease Performance Actually Tested?
Dropping point is only one of several standardized tests used to characterize a high-temperature grease. Static oxidation stability is measured with an oxygen pressure-vessel ("bomb") method under ASTM D942, though the standard itself states this does not predict dynamic in-service behavior. The tests that most directly answer "how long will this grease actually lubricate a running bearing at temperature X" are dynamic: ASTM D3336 (grease life in ball bearings at elevated temperature), ASTM D3527 (automotive wheel-bearing grease life performance), ASTM D4290 (wheel-bearing grease leakage under accelerated high-temperature conditions), and the DIN 51821-2 "FE9" roller-bearing life rig. When comparing two high-temperature greases, ask each supplier which of these dynamic tests — not just dropping point — they can provide data for, at a temperature close to the buyer's real operating condition.
How Do I Choose a High-Temperature Grease for My Application?
Selection should start from the actual measured or estimated component temperature, then work through thickener chemistry, load, base-oil behavior at heat, and relubrication cadence — in that order — never from the dropping-point number alone.
1. Establish the real operating temperature
Use the actual bearing or component temperature, not room or process ambient. Frictional heat at a bearing can run well above ambient, and intermittent or peak excursions matter as much as the continuous baseline.
2. Do not select by dropping point
Request the supplier's stated maximum continuous service temperature, ideally supported by dynamic test data, and treat the dropping-point-minus-50–100°C heuristic only as a sanity check.
3. Match thickener chemistry to the full environment
Temperature is rarely the only variable. Calcium-sulfonate complex is a common choice where heat and water or corrosion apply together; polyurea suits sealed-for-life, low-maintenance electric-motor duty (subject to the compatibility warning above); bentonite/clay, PTFE, or PFPE-based products sit at the extreme end — kiln, oven, aerospace, and chemical-processing applications — where soap-thickened greases fail outright.
4. Check load and extreme-pressure requirements alongside heat
Many high-temperature applications, such as kiln cars and steel-mill equipment, are also heavily loaded. Heat resistance without adequate extreme-pressure and anti-wear performance — commonly verified via four-ball weld point, four-ball wear scar, or Timken OK load testing — can still fail under load.
5. Confirm base-oil viscosity at the actual operating temperature
Viscosity drops sharply with heat, so film-forming ability should be evaluated at the real operating temperature, not only at the standard 40°C reference point. A higher starting viscosity, or a synthetic base oil with a flatter viscosity-temperature curve, may be needed to maintain an adequate film. Specific viscosity figures are always technical-data-sheet-specific to the product.
6. Confirm the relubrication interval for that temperature
Ask for the interval the supplier actually recommends at the buyer's stated operating temperature, not a generic data-sheet figure.
7. Do not assume high-temperature equals food-safe, or the reverse
NSF H1 (food-grade) status is an independent property governed by a different part of the formulation. An oven-conveyor food-processing application must be verified as NSF H1-registered separately from its temperature rating.
8. Request a batch Certificate of Analysis
Dropping point and other properties can vary batch to batch within a specification tolerance, so a batch-specific Certificate of Analysis is a more reliable comparison basis than a typical-value data sheet alone.
Sourcing High-Temperature Grease: Packaging, Export Documents, and RFQs
HS classification
Formulated high-temperature greases are most commonly classified under HS 3403 (lubricating preparations) — typically the 3403.19 sub-heading for mineral-oil-containing formulations, or 3403.99 for non-petroleum/fully synthetic formulations such as PFPE-based products. This is a starting reference only: the correct heading depends on the finished product's exact composition and the importing country's customs interpretation. Always confirm the applicable HS code with a licensed customs broker before quoting trade terms.
Packaging and order quantities
High-temperature greases ship in the same standard packaging range used across the wider grease category, from cartridges through bulk drums. Minimum order quantities vary by pack size and supplier and should always be confirmed directly rather than assumed:
| Pack Format | Typical Use | Indicative MOQ Range |
|---|---|---|
| 400 g cartridge (12/case) | Standard grease guns; maintenance/service packs | Roughly 500–2,000 cases per SKU — verify with supplier |
| 1–2 kg tub/sleeve | Automotive/industrial aftermarket | Verify with supplier |
| 5 kg pail | Small workshop quantities | Verify with supplier |
| 18 kg pail | Industrial standard | Roughly 100–500 pails — verify with supplier |
| 50 kg drum | Mid-size industrial supply | Roughly 50–200 drums — verify with supplier |
| 180 kg (200 L) open-head drum, UN 1A2 | Bulk industrial supply | Roughly 20–80 drums — verify with supplier |
Grease is typically packed in a UN 1A2 open-head, follower-plate-compatible drum rather than the UN 1A1 closed-head drum used for liquids. These figures are indicative starting ranges only — Altonex Global does not set or guarantee supplier MOQs; confirm the exact number in the RFQ.
Export documentation
A typical high-temperature grease export shipment requires a Commercial Invoice (broker-confirmed HS code, quantity, Incoterms), a Packing List (drum/pail count, weights, container seal), a Bill of Lading (an original is required for letter-of-credit transactions), a batch Certificate of Analysis covering the actual dropping point and, where available, oxidation-stability results, a Safety Data Sheet in the 16-section GHS format, a Certificate of Origin where preferential tariff schemes apply, and — for some destination markets — a pre-shipment inspection certificate under regimes such as SONCAP (Nigeria) or KEBS PVoC (Kenya). Confirm the current requirement for the destination market before shipment.
What to include in a high-temperature grease RFQ
- The component/application and the actual measured or estimated operating temperature — continuous and peak/intermittent
- NLGI grade required
- Preferred or required thickener system, and any incompatibility constraint from the grease currently in service
- Minimum dropping point and the supplier's stated maximum continuous service temperature — request both
- Available dynamic life-test data (D3336/D3527/D4290/FE9) near the actual operating temperature
- Extreme-pressure/anti-wear requirement if the application is also heavily loaded
- Base-oil viscosity range appropriate to the operating temperature and speed
- NSF H1 requirement, if incidental food contact applies — request it separately
- Recommended relubrication interval at the stated operating temperature
- Packaging format and quantity per SKU
- Incoterms 2020 and port of loading
- Required documents (batch COA, SDS, Certificate of Origin, pre-shipment inspection certificate if applicable)
- Lead time and payment terms
Sourcing High-Temperature Grease on Altonex Global
Altonex Global is a B2B discovery and RFQ marketplace connecting export buyers with lubricant suppliers — it is never the seller of record, and it does not set or guarantee any supplier's price, MOQ, or specification claims. Because thickener chemistry, dropping point, and actual service temperature vary product by product, the most reliable way to source a high-temperature grease is to specify the real operating condition and the required test data directly to a supplier, rather than relying on a single headline number. Buyers can review the High-Temperature Greases category to identify relevant listings and use each supplier's Request a Quote or Contact Supplier option to exchange technical data sheets, dynamic test data, and export documentation directly. For related sourcing guides across the lubricants and auto-parts categories, visit the Altonex Global Knowledge Hub.