Wide Inner Ring
Including triple seal design for severe contamination conditions, stainless steel units for corrosive environments, and high durability bearings for demanding applications.
ISB Wide Inner Ring Bearings Numbering System
These bearings are manufactured to suit either Metric shafting or Imperial shafting. There are three series, but only the UC and UK types are manufactured in all three.
The Series are:
2 -- series Light series
3 -- series Medium series
X -- series Narrow Outer Ring, Medium series - slightly less capacity than 3 -- series.
UC type and UK type are manufactured in all three series. All other types are only manufactured in 2 -- series.
The rest of the part number, for metric bore bearings, is made up of the shaft size in a code which is the same code used with Single Row Deep Groove ball bearings. Thus part number UC205 tells us the bearing has a 25mm (5 x 5) bore.
All other measurements are metric no matter whether the bore is imperial or metric. Thus, for bearing with imperial bore, ISB use the metric part number for bearings with the same dimensions (except the bore), and then add on the Imperial bore size in 16ths.
This is perhaps best explained if we take an example from the ISB catalogue shown below:
Part No. Bore Size O.D. Inner Ring (W) Outer Ring (W)
UC 205-13S 13/16" 52mm 34mm 17mm
UC 205-14S 7/8" 52mm 34mm 17mm
UC 205-15S 15/16" 52mm 34mm 17mm
UC 205 25mm 52mm 34mm 17mm
UC 205-16S 1" 52mm 34mm 17mm
Because the bearings all share the same dimensions, apart from the bore size, they have a common "main" part number which is the part number of the bearing when it has a metric bore.
The UK series bearings have tapered bores (ratio 1:12) to enable them to be mounted on adaptor sleeves. Because it is the adaptor sleeve that enables the bearings to be mounted on either Imperial or metric shafts, the part number only indicates the nominal metric bore size. Thus part number UK 205 can be mounted on an adaptor sleeve with either a metric (20mm) bore or an imperial (3/4") bore.
ISB Adaptor sleeves are, as their name suggests, steel sleeves that fit between the bearing and the shaft, allowing one bearing to suit different shaft sizes (metric or imperial) and lock the inner ring of the bearing onto the shaft.