SN stands for solvent neutral, a grade name traditionally used for solvent-refined mineral base oils. The number refers to viscosity, and SN150 is a light grade used as a blending base for finished lubricants. Recycled, also called re-refined, base oil is made from used lubricating oil and sold under the same viscosity grade names.
How re-refined base oil is made
Used oil is collected, then water, fuel and solids are removed. The oil is distilled under vacuum to separate base oil fractions, and then finished by hydrotreating, solvent extraction or clay treatment to improve colour, stability and odour. The process strongly affects quality, so two products with the same grade name can differ.
Parameters to compare
- Kinematic viscosity at 40 °C and 100 °C. SN150 is typically around 30 cSt at 40 °C and about 5 cSt at 100 °C, but values vary by supplier.
- Viscosity index (VI)
- Flash point (COC) and pour point
- Colour (ASTM D1500) and density at 15 °C
- Sulfur, water content and acid number (TAN)
Applications
- Engine oil and industrial lubricant blending
- Hydraulic and gear oils
- Metalworking fluids
- Process oils
Packaging and transport
Base oil moves in steel drums of about 180 to 200 litres, in IBC containers and, for larger volumes, in ISO tanks, flexitanks or bulk tankers. Confirm the loading option and the net weight per unit with the supplier.
