SN500 Base Oil: virgin vs re-refined, specifications and uses
SN500 is traded in virgin and re-refined forms. The name indicates relative viscosity, not the refining route or a complete specification, and must not be confused with an API engine-oil service category.
Reviewed 8 September 2026
Where this grade sits
A heavier solvent-neutral trading grade than SN150, commonly evaluated as a high-viscosity component in lubricant formulations.
Common formulation contexts
- Heavier lubricant and industrial-oil blends
- Gear, engine or general-purpose formulations only after complete qualification
- Increasing blend viscosity alongside lighter base stocks
Virgin vs re-refined
Virgin base oil
Produced from refinery base-stock streams. Ask for the named producer, current TDS and batch COA; the word virgin alone does not define Group, viscosity or performance.
Re-refined base oil
Produced from used lubricating oil through re-refining. Ask for process disclosure, feedstock controls, batch consistency and the same complete test panel required for virgin material.
What to verify on the COA
Kinematic viscosity at 40°C and 100°C
Confirms the actual viscosity profile of the offered batch.
Viscosity index
Shows how strongly viscosity changes as temperature changes.
Flash point and pour point
Useful for handling, storage and low-temperature screening.
Colour, sulfur and density
Support identification and comparison, but no single value proves overall quality.
Test methods and batch reference
Results are meaningful only when the method, date and sampled batch are clear.
RFQ checklist
- State virgin or re-refined explicitly.
- Send your target values and permitted tolerances.
- Ask for current TDS, SDS and batch-specific COA.
- Confirm quantity, packaging, origin, loading point and Incoterm.
- Approve a representative sample when formulation risk is material.
Buyer questions
Is every SN500 offer technically identical?
No. Source, refining route and producer limits differ. Compare the current batch COA with your own acceptance limits.
Can colour determine quality?
No. Colour is one observation only; viscosity, VI, flash point, pour point, sulfur and application testing matter.