SKF SONL housings are designed to be used with oil lubrication, and they offer a number of advantages over other types of housing. One of the key benefits of these housings is their ability to handle high speeds and heavy loads, making them an excellent choice for a wide range of applications. They have a strong, stiff design and are characterized by a number of built-in features that maximize the effects of the lubricant and extend bearing service life.

SONL housings block are made up of grey cast iron as standard. SONL housings series are painted black (RAL 9005) using water-based alkyd/acryl paint. The paint protects the housing in accordance with ISO 12944-2, corrosively category C2 (i.e. exterior atmospheres with low levels of pollution, and interior atmospheres where condensation may occur). The paint is not affected by most lubricating or engine oils, cutting fluids, or alkalescent washing chemicals. Housings can be repainted with most water or solvent based 1- or 2-component paints. Unpainted surfaces are protected by a solvent-less rust inhibitor.

SONL plummer block housings are dimensionally interchangeable with the earlier SOFN housings in the 2(00) and 5(00) series. 3(00) and 6(00) series SOFN housings are still available.

A labyrinth seal consists of a shaft sleeve and a labyrinth ring, to form a multi-stage labyrinth. The sleeve has a clearance fit on the shaft while the labyrinth ring is stationary and mounted in the housing with an O-ring. To guide the oil pick-up ring, one shaft sleeve is provided with a groove.

In high-temperature applications, where an oil pick-up ring is used, auxiliary cooling tubes should be installed. They use water, which has to be provided via an external system, to cool the oil in the housing. The pressure of the cooling medium should not exceed 4 bar. Oil cooling tubes are available in different sizes. Depending on the need, one or two cooling tubes can be installed via the oil outlet holes in the housing base. Detailed mounting instructions are provided with the products. Oil cooling tubes are identified by the basic designation AVA-0001.

Circulating oil lubrication system, SKF recommends using SONL .. RA housings. These housings are designed for bearings that are lubricated from the side and require a slightly higher oil level than spherical roller bearings.