How to identify an unknown engineering component
A practical method for identifying any unmarked or unfamiliar part: markings, geometry, context and documentation.
Start with what is written on it
Clean the part and look for stamped, etched, moulded or printed text. Part numbers are often split across faces or hidden under paint.
Raking light from a torch held low across the surface makes stamped characters readable.
Record the geometry
Measure the defining dimensions — bore, outside diameter, thread, pitch, pin count. A single accurate measurement often narrows the field more than a photo.
Note the mounting method and how it connects to its neighbours.
Use the context
Where the part was fitted tells you its job: the machine, the circuit, the fluid, the speed. Photograph it in place before removal if you can.
Check against documentation
Equipment manuals, parts lists and wiring schedules frequently list the exact part. Treat any identification as a hypothesis until it matches a manufacturer source.