What this product reference covers.
Open gear lubricant protects exposed or partially enclosed large gear sets where adhesion, load carrying, contamination exclusion and application rate are central.
Products within the family.
Names used in commerce can overlap. Use the nominated standard and exact grade rather than relying on a generic product label.
Fluid open-gear lubricant
Fluid open-gear lubricant is a recognised open gear lubricant category whose exact composition, grade limits and suitability must be confirmed from the governing specification and equipment requirement.
Grease-type open-gear lubricant
Grease-type open-gear lubricant is a recognised open gear lubricant category whose exact composition, grade limits and suitability must be confirmed from the governing specification and equipment requirement rather than inferred from the generic label.
Solvent-diluted lubricant
Solvent-diluted lubricant is a recognised open gear lubricant category whose exact composition, grade limits and suitability must be confirmed from the governing specification and equipment requirement rather than inferred from the generic label.
Synthetic high-viscosity open-gear fluid
Synthetic high-viscosity open-gear fluid is a recognised open gear lubricant category whose exact composition, grade limits and suitability must be confirmed from the governing specification and equipment requirement rather than inferred from the generic label.
What the product is built from.
| Component | Technical role |
|---|---|
| Mineral, synthetic or renewable base fluid | Provides the principal lubricating film and viscosity-temperature foundation. |
| Anti-wear / extreme-pressure system | Protects loaded contacts where the application requires it. |
| Antioxidant and corrosion inhibitors | Control ageing, deposits and surface corrosion. |
| Application-specific additives | Tune detergency, friction, demulsibility, air release, tackiness or seal compatibility. |
Define the decision before selecting the panel.
- 01
Confirm new open gear lubricant identity, grade and fitness for the intended application.
- 02
Detect contamination, degradation, mixing or storage-related change.
- 03
Investigate abnormal equipment, combustion, filtration or handling behaviour.
- 04
Establish a representative baseline for later comparison.
- 05
Support specification, maintenance and root-cause decisions with corroborated evidence.
What each result contributes.
“High” and “low” are directional investigation prompts, not pass/fail decisions. Corroborate them using the correct specification, baseline and companion evidence.
| Test / parameter | Typical methods | Why it matters | Possible causes when high | Possible causes when low |
|---|---|---|---|---|
| Kinematic viscosity | ASTM D445 / ISO 3104 | Confirms grade and detects dilution, shear, oxidation or mixing. | Oxidation, wrong oil, soot, evaporation or heavy contamination. | Shear, fuel/solvent dilution, wrong grade or lighter make-up oil. |
| Acid number | ASTM D664 | Trends acidic constituents, oxidation and contamination against a new-oil baseline. | Oxidation, overheating, acidic contamination or wrong fluid. | Fresh oil, make-up dilution or formulation difference. |
| Water | ASTM D6304 | Quantifies moisture relevant to corrosion, additive loss and film strength. | Condensation, cooler/seal leak, washdown, storage or sampling contamination. | Dry operation or dehydration; hot sampling can reduce free-water representation. |
| Elemental analysis | ASTM D5185 with PQ / ferrography where needed | Screens wear, contaminants and additive chemistry within method limitations. | Wear, corrosion, dirt, additive source, wrong oil or maintenance debris. | Stable wear, dilution, filtration or particles too large for ICP response. |
| FTIR condition | ASTM E2412 trending | Tracks oxidation and selected molecular contaminants against a comparable reference. | Heat, extended service, contamination or depleted antioxidant reserve. | Fresh oil, make-up dilution or a non-comparable baseline. |
| Ferrous debris / PQ index | Direct-reading ferrous density / PQ method; laboratory procedure | Responds to ferromagnetic debris including particles larger than routine ICP can efficiently detect. | Active gear, bearing, liner or steel-component wear; corrosion scale or maintenance debris. | Stable wear or little ferrous debris; a low value does not exclude non-ferrous or very fine wear. |
| Analytical ferrography / wear-particle morphology | ASTM D7690 or documented microscopic procedure | Examines particle size, shape, colour and concentration to distinguish rubbing, cutting, fatigue, corrosion and contaminant debris. | More severe particles, increasing concentration or a morphology consistent with active distress. | Few captured particles; poor agitation, settling or sampling away from the wear path can reduce recovery. |
| Wear / load-carrying performance | ASTM D4172; ASTM D2783 or application-specific gear/EP test | Characterises anti-wear or extreme-pressure performance for product qualification and comparative investigation. | For scar diameter: poor anti-wear response, contamination or depleted/additive-incompatible oil. | For scar diameter: stronger film/additive response; results do not directly predict a specific machine's wear rate. |
| Particle count / cleanliness | ISO 11500; reporting to ISO 4406 | Quantifies solid-particle cleanliness where component clearances and servo reliability are sensitive. | Dirt ingress, active wear, ineffective filtration, maintenance debris or wrong sampling point. | Effective filtration or clean new oil; settling, dilution or non-representative sampling can under-report. |
| Copper corrosion | ASTM D130; ISO 2160 | Screens corrosivity toward copper-containing bearings, coolers, bushings and yellow-metal components. | Reactive sulfur, acidic degradation, contamination or formulation incompatibility; report uses a corrosion rating rather than concentration. | A low corrosion rating is favourable but does not rule out in-service copper wear. |
Condition-monitoring application.
Once the product is in service, the question changes from “does it meet a product requirement?” to “what has changed, why, how confident are we and what action is proportionate?”
- 01Use a stable, representative sampling point and document operating hours, top-ups, transfers and maintenance.
- 02Trend method-consistent results rather than treating one value as a complete diagnosis.
- 03Separate new-product conformance from in-service condition and machine-wear questions.
- 04Escalate correlated evidence and rate of change; confirm surprising results before major action.