Certified Lubrication Specialist Practice Test 2026 – All-in-One Guide to Master Your Certification!

Specific gravity is the ratio of a lubricant’s density to the density of water. It’s a dimensionless measure that uses water as the reference point (density of water is 1.00 g/cm³ at 4°C). This means a lubricant with density less than water has a specific gravity below 1, while a heavier oil would have a value above 1. This concept helps compare lubricants without units and informs about buoyancy and compatibility in systems. In contrast, viscosity index relates to how viscosity changes with temperature, grease consistency describes firmness, and water separation is about how well water separates from oil.