What should be recorded when the marking on an old bearing is partly unreadable?

LILY Bearing | 2026-10-28

Best answer

An incomplete marking is evidence, not a blank to fill by guessing

Photograph the whole marking and transcribe uncertain characters explicitly, such as “last two characters unreadable.” Record the manufacturer mark, machine position and packaging information if these remain available.

The manufacturer's designation system can explain a readable code, but it cannot prove which missing code was originally present. Some supplementary information may also have been abbreviated on the component. A bearing that measures like a standard size could still have a particular seal, cage, clearance or matched arrangement. Keeping uncertainty visible prevents a plausible-looking search result from becoming an invented identification that then propagates into a purchase order.

Build an identification packet that another person can use

Separate the packet into observed information, documentary information and unresolved questions.

Observed information includes photographs, nominal dimensions with the measurement method, and which parts were removed together. Documentary information includes the machine drawing, previous order and any traceable supplier label. For instance, a readable “6205” plus an unreadable suffix supports investigation of that basic designation, but does not prove whether the removed bearing was open or sealed, or which clearance was supplied. Ask the supplier to reconcile the packet with the machine requirement and identify the remaining gaps. Retain the original photographs alongside the eventual selected designation so that the reasoning can be reviewed later.