SKF SONL split pillow block housings

In SONL 217-517 and SONL 218-518, the letters give the series and the paired number lists the two bearing sizes one housing body takes. SOFN 224 BF is from the earlier series, with a different designation style, and its closing letters describe the assembly. Don't swap a housing from one series for the other without comparing base dimensions.

An added block, as in SONL 218-518 K7, marks a variant of the same size and must be copied. The designation covers the housing only; the bearing, sleeve, oil ring and seals each have their own part numbers.

An oil-lubricated housing has to sit level, with oil at the specified height. Too little oil and the ring cannot lift it; too much and the oil churns, heats up and escapes through the seals. The sight glass or level indicator belongs to the assembly and should be checked at every shutdown.

Seals are non-contact labyrinth seals, since the speed rules out rubbing lips. That means careful shaft installation and a setting free of direct splashing. If the equipment runs very hot, it may also have oil cooling; mention that in your request.

Send the full housing designation and quantity, along with the bearing designation, shaft diameter, speed and operating temperature. Tell us whether the position is locating or non-locating, whether the shaft passes through or ends inside the housing, and which oil you use. With the machine stopped, a photo of the sight glass and one of the base help confirm the series.