1. Start with the motion task
Confirm that the mechanism genuinely needs a follower running on a cam, guide or mating track. If the design calls for constrained, highly accurate linear translation along a rail, a linear guideway may be the more appropriate architecture. Product names should follow the mechanism, not the other way around.
2. Measure the interface
For the EP-KR / EP-KRV series, record outside diameter D*, outer-ring width C, D1, stud thread, G1 and the B/B1/B2/B3 dimensions. Check C1 and the minimum corner radius where the adjacent construction is tight. These measurements create a reliable shortlist even when the original marking is incomplete.
3. Check duty and environment
Operating speed, repeated-cycle pattern, shock, track hardness and finish, contamination, washdown, temperature and lubrication all influence a real application. A catalogue speed reference is useful for comparison but is not a standalone approval for a machine.
4. Use cross references carefully
An IKO CF or WERB NAKD name can point to a likely EP size. Confirm the dimensions and ordered features before treating it as a replacement. Where the source material does not establish exact feature parity, the site deliberately uses “reference” rather than “drop-in interchangeable.”