2710.20.05 - Testing under 25 degrees A.P.I.

This HTS classification, 2710.20.05, covers specific distillate and residual fuel oils that have a petroleum gravity testing below 25 degrees A.P.I. These are heavier fractions of petroleum compared to lighter oils, often characterized by their density and viscosity. This category is distinct from its sibling, 2710.20.10, which covers similar fuel oils but with a petroleum gravity of 25 degrees A.P.I. or more, indicating a less dense product.

The subdivisions within 2710.20.05 further refine the classification based on the Saybolt Universal viscosity at 37.8°C, a key indicator of oil thickness and flow characteristics. Subcategory 2710.20.05.10 encompasses "No. 4-type fuel oils," which have a viscosity ranging from 45 to 125 seconds. This represents a moderately viscous fuel oil.

In contrast, subcategory 2710.20.05.20 is for "heavy fuel oils," characterized by a Saybolt Universal viscosity exceeding 125 seconds, signifying a very thick and viscous product. The residual subcategory, 2710.20.05.50, is reserved for other distillate and residual fuel oils not meeting the specific viscosity criteria of the preceding subcategories, but still falling within the broader scope of fuel oils with a gravity below 25 degrees A.P.I.