ISO Bearings

A word of caution, regarding IRC for those selecting ISO deep groove ball, cylindrical roller, and spherical roller bearings, is the “Normal” IRC shown in the tables for these bearings is not sufficient for these bearings if the bearing employs a “heavy” shaft fit. A heavy fit in most cases requires a “C3” IRC as a bearing with a “Normal” IRC could be too tight. A light to medium fit with a relatively high operating speed that generates heat also requires a “C3” IRC. If both a heavy fit is used along with a high speed, a “C4” IRC is typically required. Very few bearings with “Normal” IRC are used or stocked, with “C3” bearings being the most popular. For complicated applications, we recommend that users of our bearings contact our sales department for specific fitting and clearance recommendations.

Standard Internal Radial Clearance values for deep groove ball, cylindrical roller, and spherical roller bearings are found in Tables XV through XXII. Please note that there are different standards for metric deep groove ball bearings and inch ball bearings, as well as ISO cylindrical roller bearings and domestic cylindrical roller bearings. Also, the IRC values differ for straight bore bearings versus bearings with a tapered bore. There are no standards for tapered roller bearings. “Clearance” values for these bearings are expressed axially as “lateral” or “Bench End Play” (BEP) and are designed and specified for each application.

Bearing Number	Bore Dia	Outer DIa	Width	Size
50 mm x 90 mm x 20 mm ISO NP210 cylindrical roller bearings	Normal Duty	Setscrew Ball Bearing	203 Series	Zinc
533,4 mm x 635 mm x 50,8 mm ISO LL575343/10 tapered roller bearings	Normal Duty	Grip Tight Ball Bearing	216 Series	Cast Iron
17 mm x 26 mm x 7 mm ISO 63803-2RS deep groove ball bearings	Normal Duty	Setscrew Ball Bearing	206 Series	Cast Iron
480 mm x 700 mm x 165 mm ISO 23096 KW33 spherical roller bearings	Normal Duty	Setscrew Ball Bearing	206 Series	Cast Iron
15,875 mm x 53,975 mm x 21,839 mm ISO 21063/21212 tapered roller bearings	Normal Duty	Setscrew Ball Bearing	207 Series	Cast Iron
280 mm x 380 mm x 100 mm ISO NN4956 cylindrical roller bearings	Normal Duty	Setscrew Ball Bearing	204 Series	Cast Iron
240 mm x 440 mm x 120 mm ISO NU2248 cylindrical roller bearings	Intermediate Duty	Setscrew Ball Bearing	205 Series	Zinc
ISO 7200 BDF angular contact ball bearings	Normal Duty	Setscrew Ball Bearing	210 Series	Cast Iron
ISO 53417U+U417 thrust ball bearings	Normal Duty	Eccentric Collar Ball Bearing	205 Series	Cast Iron
ISO 81107 thrust roller bearings	Normal Duty	Eccentric Collar Ball Bearing	206 Series	Cast Iron
ISO 7017 CDT angular contact ball bearings	Normal Duty	Setscrew Ball Bearing	207 Series	Cast Iron
40 mm x 90 mm x 23 mm ISO 20308 spherical roller bearings	Normal Duty	Setscrew Ball Bearing	204 Series	Cast Iron