All of the ball bearings in my content library are metric (DIN, ISO, etc.). I typically use inch size bearings. How can I obtain American sized content?
To my knowledge R series does not exist in Acad/m. The parts libraries originated in Germany in the mid 90's so there are more selections for ISO & DIN.
ACM provides some common ANSI standard for bearing. During installation, do remember to check the ANSI standard content to be included during installation, or you can repair/add feature operation to add the ANSI standard content.
To my knowledge a good installation with ANSI as the main standard does not contain "R" series bearings. It is a deficiency in ACAD/m.