The main sizes of the tapered roller bearings comply with DIN ISO 355 and DIN 720. Dimensional and running tolerances correspond to tolerance course PN acc. to DIN 620. These tolerance classes are standard and so are well suited for most applications.
The bearings are separable. This implies the bearing parts could be fitted independently of each different. The bearings are provided without seals. They can be lubricated with grease or oil from the side.
The rollers are processed to create pore-like micro indents in the surface of the steel (rolling contact surface area and roller brain). This microstructure helps maintain an oil film that’s perfect for tapered roller bearing applications. Improved oil film retention drastically inhibits surface damage, achieving more than eight times higher durability and equal or greater seizure resistance in comparison to conventional products.
Much better lubricant oil accumulation and retention (simpler to form oil film) in the roller surface plays a part in 10% lower friction by low speeds in comparison to conventional products.
Tapered roller bearings can accept high radial and axial loads. Axial loads are absorbed in only one way. For axial counter support another bearing installed inverse is required. Suitable for medium speeds.
Higher efficiency transmission systems are seen as key to increasing energy economy, so NSK attempt to develop a high reliability bearing with the capacity of overcoming these hurdles.
To improve fuel economy, there’s been a shift to using less lubricant and/or decrease viscosity lubricant in tranny systems. Subsequently, tapered roller bearings in transmissions will be being at the mercy of increasingly severe lubrication circumstances, increasing the chance of lubrication essential oil film 
depletion (lean lubrication circumstances), surface damage, and bearing seizure.