Petrochemicals & Petroleum Products #5831738

Bitumen is classified by the depth to which a standard needle will penetrate under specified test conditions. This pen test classification is used to indicate the hardness of bitumen, lower penetration indicating a harder bitumen.
Bitumen 30/40, Bitumen 40/50, Bitumen 50/60.etc

Passing air through bitumen at elevated temperature can be used to alter its physical properties for certain commercial applications. The degree of oxidation can range from very small, often referred to as air-rectification, or semi-blowing, which only slightly modifies the bitumen properties, through to full blowing, whereby the properties of the bitumen are significantly different to penetration grade bitumens.
Bitumen R85/25 Grade.etc

Cut-backs are bitumen preparations in which the viscosity of the binder has been reduced by the addition of a volatile solvent, normally derived from petroleum.
Bitumen MC/250 .etc

Bitumens are also graded and specified by their viscosity at a standard temperature (typically 60C). V1500.
Bitumen V1500.etc